Let's now take a look at the Demonology tree. Out of all the trees, Demonology has always been about utility. Obviously the most pet-centric spec, Patch 3.0.2 brings interesting synergies with the pet and Warlock that also brings significant gains in DPS. It's also still a great PvP spec, although Warlocks who choose to pursue SL/SL take a hit from the survivability nerfs in Demonology and miss out on some cool 51-point toys.
On the first tier, we already discussed the nerf to Demonic Embrace, which now only grants 10% total Stamina instead of 15%. The Spirit penalty was removed, however, and it actually matters because we actually get spell power gains from Spirit through Fel Armor. Five points here is mandatory. There's also Improved Imp, which we'll skip because we won't be using the Imp much as a Demonologist, anyway.
And then there's Improved Healthstone, which I highly recommend whether you raid or PvP. It's notable that when I tested it in Beta, players are no longer allowed to possess more than one Healthstone, regardless of rank. Because of this change, you might as well have the best one. Your raid or team will thank you for it.
On the second tier we'll find Improved Health Funnel, which was buffed to grant a mitigation mechanic while our pet is under the effect of Health Funnel. I'd normally say take it, but we'll have our hands full with other talents later on. If you use your pet to tank a lot, this talent helps. Otherwise, you can skip it.
On the other hand, you have to put three points in Fel Vitality, which rolls Fel Intellect and Stamina together. This one is a no-brainer. Demonic Brutality is a tougher choice. This is the buffed Improved Voidwalker which also increases the DPS of our Felguard. This is about as close as we'll get to an Improved Felguard for now, so it just might be worth investing in.
Improved Succubus in tier three has been reworked to a more usable form by making Seduction instant cast, which is awesome. It's not like we ever used her for Lash of Pain or Soothing Kiss, anyway. If you really want pure utility, pick this up as it will also situationally be handy in PvP. Despite the improvement, though, I'd much rather spend three points in Demonic Aegis on the same tier for the spell power bonus to Fel Armor.
Two key talents are also on the third tier -- the weaker but more accessible Soul Link and life-saving Fel Domination. Take them. Speaking of key talents, max out all the talents in tier four. Unholy Power opens up three different talents and Master Summoner is necessary to make Fel Domination absolutely worth it.
The good news is that Demonic Sacrifice is now completely optional. If you're a fan of demon-less raiding, which I admittedly am not, then pick this up to go along with a hybrid Destruction spec. Otherwise you can skip this talent and Master Conjuror, both on the fifth tier. It's important to note, however, that Firestones and Spellstones have been reworked to be weapon buffs like Mana Oils. They no longer need to be equipped but instead are a 5-charge consumable item that grants significant bonuses to direct damage spells or DoTs.
Mana Feed on the sixth tier is a good investment, particularly because Felguards eat through their mana extremely fast. Master Demonologist is another vital talent not only for the passive benefits but because it's required for Demonic Empowerment. That's about eight talents spent on this tier, so it's good that we can skip the underwhelming Improved Enslave Demon completely.
Tier seven is a mixed bag. If you're heavy into PvP, you should probably max out Demonic Reslience, specially with the weaker Soul Link. Otherwise, you can skip it and invest in the more DPS-oriented Demonic Knowledge, which should do wonders for you in PvE. Also on this tier is the utility spell Demonic Empowerment, which I've enthused about. I like it. I have it hotkeyed. I hope you like it, too.
Past the seventh tier we will be foregoing hybridization and should be committing to full Demonology. It's also where all these master and demon synergies start falling into place. Demonic Tactics on tier nine is a flat out DPS boost that should be maxed out. We'll also need it for another cool talent on the next tier. If we plan on sending our pet into the fray -- which we should, really -- Fel Synergy will help keep it alive. The more damage we deal, the more our demons stay up. How cool is that?
Improved Demonic Tactics is on the ninth tier and gives our demons that necessary punch for Demonic Empathy. The DPS boost is moderate at 3%, but is virtually guaranteed to be up for either the Warlock or her pet at all times. It's pretty weak for something so deep in the tree, however, so I recommend skipping it. What we're not skipping, however, is Summon Felguard. No, really.
Improved Demonic Tactics will come in handy for Demonic Pact, which grants a raidwide buff whenever our pet crits. If you're a raider, you'll want this. It won't stack with Shaman totems, though, so it's only good if you have considerable spell power. If you mostly PvP, you can skip it.
Finally, we have Metamorphosis. I wanted to do a Skill Mastery on this talent because it really needs to be discussed. First of all, I honestly don't think it's a finished spell. At its best, it's a 30 second DPS boost every three minutes and a perfect panic button for PvP. It boosts a Demonology Warlock's survivability to the stratosphere because of the 600% armor bonus and snare and stun duration reductions. It's very nearly a Warlock's version of The Beast Within.
Be warned, however, that the associated abilities in demon form are situational and even downright silly. Shadow Cleave gives you a low-damage melee strike... that also hits allies. I mean, if you have 30 seconds in this godly, er, demonic form, why would you waste your GCD on a silly melee strike? Then there's Challenging Howl, an AoE taunt for those Warlocks who've always dreamed of being Tankadins. Of course, the only thing vaguely tank-ish about a Warlock in demon form is the armor, and it's not even that high. Oh, and once 30 seconds are up, you're quite certain to die.
Immolation Aura is great, though. It scales very well with spell damage and is there to teach those big, bad Warriors a lesson for picking on us. It lasts 15 seconds, so if you can't get out of melee range within that span of time, at least you're dealing some hurt. It's pretty much the best demon form ability, although you'll rarely use it while raiding. There's also Demon Charge, which is like a Warrior's Intercept. The trouble is, it works from a minimum of 8 yards, meaning you'll actually have to get close to someone you're already far away from to begin with. [CLARIFICATION: That statement was supposed to mean "you're already 8 yards away, why the hell would I charge to my opponent?"]
I don't know about you, but I was fairly certain that our strategy was to kite things, not to tank things. Pretty much everything about Metamorphosis is counter-intuitive. That said, the ability does have its uses, and can be considered a boost to DPS when raiding. Hopefully it'll still get fixed at some point and, for the love of demons, it should get a female form. Even if you go deep into Demonology, you're completely excused if you skip Metamorphosis.