First up, we should talk about Elemental Shamans, because I feel like going in order of the talent panel. Before we do, though, we'll talk about a change that will be of concern to almost any and all shaman: the loss of downranking.
Not all shamans do this, but enough do that it bears mentioning. If you use a downranked Earth Shock to interrupt spells you don't have to worry, as Blizzard has a replacement spell for you. Wind Shock is trainable at level 16, so even if your shaman's not at the level cap you'll get something this patch. If you used downranked totems to flush out rogues or for other uses in PvP, or downranked your healing spells to conserve mana, then you have more to be concerned about. Combined with the fact that you can only use one mana or health potion per fight (the potion sickness debuff is now gone, but the effect is still in game - if you drink a pot in a fight, you won't be using another until the fight ends) you will have no choice but to change how you heal or DPS in instances and raids.
Other changes to keep in mind that affect all shamans are many spells now working off of a percentage of base mana (the amount of mana you would have naked, with no gear on) and the new buff system. Totems now affect an entire raid, rather than just your party, and most totems last five minutes. Bloodlust/Heroism now inflict a debuff that prevents their use for five minutes, ending chain-casting heroism, but their effect is now raid wide as well. Totems are also in the physical school now, meaning that if you're silenced, or interrupted/locked out from a specific school, you should still be able to drop them. (I'm not 100% sure on the silence, because amazingly I've managed to never be silenced my entire time in the Beta. I have weird luck.) Also, many totems have changed effects entirely: Windfury Totem, Wrath of Air Totem, Strength of Earth Totem and Flametongue Totem to name just a few. Grace of Air is gone, folded into SoE.
We know spell coefficients are changing due to the existence of debuffs that can be applied to nature damage like Lightning Bolt and Chain Lightning. So you'll probably see a DPS drop when soloing or otherwise not running in a group with Curse of the Elements. Shamans should keep in mind that, if you're in a group or raid with an elemental and enhancement shaman, the elemental shaman gets no benefit at all from the enhancement's Stormstrike debuff anymore.
Several talents have been moved or changed: Elemental Devastation drops to the second tier to make it more reachable for enhancement shaman, Elemental Focus is now a pre-requisite for Call of Thunder, which now also requires 20 points to pick up. Elemental Fury, a new talent, is the pre-requisite for Lightning Mastery. Elemental Precision now adds only 3% hit rating at 3 points invested, but will reduce threat by 30% at the same level. Elemental Oath, the new talent following Elemental Mastery, will add a spell critical aura similar to Moonkin Aura (and which will not stack with Moonkin Aura in the new buff system) when you critically hit with spells.
Improved Fire Nova Totem now applies a slowing effect. Useful both for PvP and in trying to corral mobs for AoE purposes. Elemental Shields no longer functions like a kind of Resilience, instead simply reducing all physical damage taken by 6%. Hmm. 6% reduction to all crits, physical and spell, or 6% physical damage reduction, with absolutely no help against magic damage at all. Well, I guess it's three talent points you know you won't be spending, right?
Totem of Wrath is pretty drastically changed. First off, unless I've missed a change somewhere, it provides a kind of debuff to all enemies within 40 yards, making it more likely that they will be critically hit by spells. This means it stacks with Elemental Oath and Moonkin Aura, because it's not buffing you, it's debuffing them. Secondly, due to changes in Wrath of Air and other totems which we'll be covering, Totem of Wrath is now a flat damage boosting totem. While this means that your average elemental shaman won't be able to drop this totem and Flametongue Totem at the same time (Flametongue now adding outright spell damage and healing) it also means that a party or raid with two shamans can easily have Wrath of Air and Flametongue and they don't cancel each other out via the new buff system. I'm sort of cautiously optimistic that there will be more of a reason for non elemental shamans to drop fire totems now.
Lava Flows, Astral Shift, Storm, Earth and Fire and Thunderstorm are the new talents that get you from 41 to 51 points in the tree. Astral Shift is pretty obviously a PvP oriented talent, although it might come in handy in PvE from time to time. Lava Flows won't have the nice critical bonus to Lava Burst (since you won't get Lava Burst until you're level 75) and so I'd say it's up to you if you really want your Flame Shock range extended that badly. You might, if you take full Storm, Earth and Fire to get the Chain Lightning cooldown reduced by 2.5 seconds and therefore have 50% more damage from your Flame Shock DoT. You'll also get an extra 5 yard range on Earth Shock... I'm not sure how much that will matter. And Thunderstorm is the elemental shaman's mana regeneration tool in PvE, and the 'Get the heck away from me' tool for PvP.
Finally, Flametongue Weapon has been changed to better fit its role as the Elemental Shaman Weapon Imbue of Choice. (TM.) Yes, I know it's an enhancement ability. We'll be talking more about it when we get to enhancement, which is now.
One really big change for enhancement shamans is how you'll want to gear. With Agility granting 1 AP and Strength granting 1 AP (prior to Tuesday's patch, Str grants 2 AP) mail with Agi and AP on it becomes more attractive. In addition, the talent Mental Dexterity will allow you to gain AP from a high Int, making mail with int on it more attractive. A lot of gear that currently has strength on it (like your set pieces and PvP gear) will be converted to attack power instead. This is most likely also the reason for the Ancestral Knowledge change, giving you intellect instead of mana to synergize well with Mental Dexterity.
Thundering Strikes is changed to increase spell and melee critical hit chance. The reasoning for this change and most of the other changes you'll see to enhancement is to encourage more use of shocks and the new Maelstrom Weapon ability. In effect, you will be using a lot more spells, so TS will be helping you crit across the board, not just on melee damage. Shamanistic Focus isn't a proc anymore, just a flat reduction in shock costs. Improved Shields replaces Improved Lightning Shield and has that talent's effects plus bonuses for Water Shield and even Earth Shield for resto shamans. Elemental Weapons moves down the tree and replaces Rockbiter with Earthliving. (As far as I know, Rockbiter is gone, but I haven't looked for it.) Anticipation is dropped to three ranks but gains disarm reduction, while Toughness now only reduces movement slowing effects by 30%. Weapon Mastery is 3 points for the same effect it now has for five.
Since Windfury Totem (not Windfury Weapon, that's unchanged) now provides melee haste instead of a chance to proc a melee attack, Improved Windfury Totem simply adds more haste, replacing Improved Weapon Totems. Unleashed Rage moves down the tree but provides the same effect (raidwide), Stormstrike is now limited to the shaman who casts it, and there are two ranks of Improved Stormstrike as well. No more rogues or elemental shamans eating up your nature damage debuff, if that bothered you.
Lava Lash is an entirely new ability that seems designed around getting shamans to move away from the WF/WF Slow/Slow weapon combo. So far there's lots and lots of testing on how much damage it does, if it's worth losing double WF to use Flametongue on the offhand, and for a while people were actually doing more damage in elemental gear with this talent, which led to some adjustments. I'm still playing with it myself, but just having another instant attack makes me happy. Earthen Power is the new talent that makes Earthbind Totem also clear snares on you when you drop it. Static Shock was a pretty good cartoon based on the Milestone comic, and now will also be a shaman ability allowing you to have more lighning shield orbs and giving you a chance for those orbs to randomly discharge when you're damaging someone.
Maelstrom Weapon we've talked about, but it bears repeating: the spell description reads "When you deal damage with a melee weapon, you have a 100% chance to reduce the cast time of your next Lightning Bolt, Chain Lightning, Lava Burst, Lesser Healing Wave, Chain Heal or Healing Wave spell by 20%. Stacks up to 5 times. Lasts 30 sec" when you spend 5 points to max the ability, and the variety of spells affected by it means that it's a great, versatile tool for the enhancement shaman. Need a fast heal to keep yourself or someone else up? Throw an instant off. Want to do AoE damage, an instant CL comes in handy. When you hit 75, you'll use this in conjunction with Flame Shock and Lava Burst quite frequently, but it's worth taking even at 70 just for all the cast times you can make instant with it. This is an excellent ability. (Edited to correct: Sadly, despite the tooltip on Beta being unchanged, Maelstrom Weapon does not work with Lava Burst anymore.)
Finally, Feral Spirt makes you feel like Thrall or Drek'Thar. The wolves have a variety of abilities, can AoE taunt, can heal you when they deal damage, can even stun. They're up for 45 seconds every two minutes. Honestly, this is the most fun I've ever had playing a shaman right here. I love this ability.
I know I'm missing out on other enhancement changes, but we do have to move on now. There's still a tree waiting for us to discuss it.
This is the tree that may or may not (depending on how you heal) feel the downranking and potion changes the strongest. Improved Shields over in enhancement is almost a must-have for resto shamans, I can't imagine not going 8 points in enhancement. This will leave you with 53 points to spend, making getting the new 51 restoration talent a bit tight. Are you going to want to? That depends.
Some players still find Riptide somewhat underwhelming. Combined with the HoT effect from Earthliving, I'm fairly interested in getting to test the spell out as an instant heal for shamans, but I would like to see the base heal increased and the base mana cost reduced. I'd also like a pony, but I'm probably not getting one of those either. It's up to you to decide if you want to spend your 51st talent point in restoration on an instant cast with a HoT component.
For the rest of the tree, the first new talent is Improved Water Shield replacing Nature's Guidance. Most resto shamans probably won't miss nature's guidance, I guess. And since you'll probably have Improved Shields anyway, Imp WS might work out to help a lot on mana regen. I don't like the idea of having to keep track of WS and cast it a lot... anything that takes up a GCD, I don't like as a healer... but that's a personal bias and doesn't really change the spells viability. The next new talent is Tidal Force, replacing Totemic Mastery (which has been folded into all totems, they all have 30 yard ranges now) which increases on use your chance to critically hit with healing spells. Since many new talents require a critical heal, this is a pretty solid talent.
Another new and in my opinion timely restoration talent is Cleanse Spirit. Restoration shamans can now remove curses, and frankly it's about time. (Cue Starcraft 2 cinematic.) Nature's Blessing changes to work with the new spell power system. We now enter into the entirely new talents past Earth Shield. We've already talked about Riptide, so we're left with Ancestral Awakening, Blessing of the Eternals, Tidal Waves, and Improved Earth Shield.
Frankly, if you've taken up to Improved Shields in enhancement to get the mana regen benefit anyway, you're tight on points by the time you get this far in the tree. Both Ancestral Awakening and Blessing of the Eternals have interesting new effects, while Improved Earth Shield just gives you more ES charges and boosts the amount it heals by 10%. I'm not going to tell you that Imp ES is bad, but I'd probably want at least Blessing of the Eternals over it for the boost to my Earthliving proc and the chance to increase my healing crits, since a crit heal is going to cost me less mana for a bigger heal and also because I'd probably also consider Ancestral Awakening over Imp ES, which relies heavily on my healing spells landing a crit. They just synergize better. But if you want to extend out how many ES charges you can keep on a tank, then Imp ES is a good ability. The five point investment in Tidal Waves (which I'd be hard pressed not to take) makes it even harder. I mean, you're going to be casting Chain Heal a lot. Getting a reduced cast time, extra healing Healing Wave every time you do?
One thing's for sure: restoration is in for a lot of changes in how we select our talents and how we go about healing, between downranking, new crit-based and proc abilities, and new spells and weapon imbues with HoT aspects to consider. Flametongue Totem becomes the new 'best in show' totem for a resto shaman, with Wrath of Air buffing all casters fairly equally. And of course, Earthliving will be your weapon imbue of choice.
It's a whole new world for all three specs, ultimately. Elemental shamans get some expanded PvP viability, enhancement shamans become a melee/caster hybird (perhaps the purest hybrid of them all) and restoration will be entering a whole new kind of healing, relying on crits and procs and HoT effects. Should be interesting to watch how it all shakes out.