All the prime glyphs are gone. Now, there are just two tiers: major and minor. In general, glyphs are much more situational and much less required (though feral has a few exceptions, which I'll note below).
Most abilities are now spec-specific; general abilities have been rebalanced to be much more useful to all specs. While this seems like a nerf, this is a good thing. Instead of having tons of non-useful abilities, now your off-spec choices are simplified and much more useful. This applies more to feral/guardians' needing to use the occasional spell; while balance/resto retain access to physical damage abilities in bear/cat form, there's no real reason to use them.
Rebirth now returns a player to 60% life. Previously, it had been 20%, making the glyph essentially mandatory. You can still glyph it if you want, but you won't have to anymore.
Faerie Fire's duration is much shorter. The debuff now automatically stacks three times (yay for ferals) but only lasts 30 seconds (boo). If you need to maintain this for your group/raid, get used to hitting a keybind for it when you have a free GCD.
Get a new ability: Might of Ursoc. This ability is like the old version of Survival Instincts; it gives you 30% more max HP and bumps your current HP up as well. Then 20 seconds later, that health goes away. Unfortunately, right now it forces you into bear form, and the effect drops as soon as you leave bear form, so it may not be that useful for non-guardians.
The feral spec as a whole plays pretty similarly to the way it did in Cataclysm. With only a few minor tweaks, you should be good to go; however, things will change quite a bit once you start leveling and get Symbiosis plus your level 90 talent choice.
Bleed debuffs are gone. Happily, you no longer have to worry about Mangle when you're in a group. Sadly, Shred has retained its orientation restrictions, so you'll still need to keep Mangle around for soloing or bosses that force you to attack frontally.
Savage Roar is now much more important. It has been reverted to the Wrath of the Lich King model and again buffs all damage instead of just auto-attack damage. This is a significant change; you will want to keep this up at all times, as your damage is pathetic otherwise. Thankfully, there's a new glyph that lets you use Savage Roar with zero combo points, Glyph of Savagery.
Crit rates have been reduced. This isn't too significant at level 85, but once you actually start leveling, you're going to have much fewer combo points to play with. It's probably best to avoid Ferocious Bite for now in your rotation, unless you're sure it will get a kill.
AoE is now more complicated. You'll need to keep Savage Roar up and also maintain a Thrash bleed. Helpfully, Swipe now generates combo points.
Stampede is gone completely. Yes, this means no more free instant Ravages, and yes, this is further proof that hunters are the kids who hog all the toys.
In contrast to feral, balance saw a much bigger slew of changes throughout the beta. Several mechanics were tried and discarded before they arrived at the current rotation, which is superficially similar to Cataclysm's but has several key differences.
DoTs have been reworked. Insect Swarm is gone. In its place is Sunfire, which is now a completely independent DoT from Moonfire. Both DoT abilities are affected by Lunar Shower, which makes movement DPS slightly more tolerable.
Eclipse mechanics have been redesigned significantly. The majority of your damage comes from cycling Eclipse as quickly as possible in order to maximize uptime of Eclipse's haste buff and the free cooldown reset on Starfall every Lunar Eclipse. The new design of Euphoria means you spend most of your time in an Eclipse instead of trying to get to one, which is cool.
Eclipse state can be charged at will. Astral Communion is a new channeled ability that lets you charge your Eclipse bar, letting you begin each fight in the appropriate state (typically one cast away from Eclipse).
Get a new burst cooldown. Celestial Alignment is a new cooldown ability that helps combat Balance's lack of ramp-up damage. When cast, it grants you the damage bonuses of both Lunar and Solar Eclipses and causes Moonfire to automatically apply Sunfire. Using this resets your eclipse energy to 0 and stops you from gaining any energy while it's up; as such, if you're using it rotationally, you'll want to use it immediately after leaving an Eclipse.
Solarcleave is dead. Mana's too tight, and Wild Mushrooms don't have the kick they used to. Hurricane has been buffed, however, and a new Astral damage variant called Astral Storm has been introduced, which will help for AoE during Lunar phases.
There are plenty more tweaks to come -- man, Sept. 25 can't come soon enough. Are you guys looking forward to the rotation changes?
Every week, Shifting Perspectives: Balance brings you druidic truth, beauty and insight ... from a moonkin's perspective. We'll help you level your brand new balance druid, tweak your UI and your endgame gear, analyze balance racials and abilities, and even walk you through PVP as a balance druid.