There is a lot planned for warlocks in WotLK: changes to existing abilities, new abilities and even talent trees. Examining each change or addition in detail would be tiresome and perhaps even fruitless, as I am pretty sure some of these things will change in later stages of development. Instead, I will take an overview approach in two parts and try to discern some important changes to the way we've played our class for the past 70 levels.
51-point talents: PvP only?
Let's zoom in right away to the top-tier talents: Atrocity, Metamorphosis and Decimate. All sounding very evil and warlocky, yes?
Atrocity is essentially an AoE Corruption, with a nice kick at the end of the DoT's duration. In PvE, it's unlikely that you'll want to blanket DoT every mob in an area, unless you're sure that they are being tanked. For the purpose of bringing a group of mobs down, Seed of Corruption should still do a neater and quicker job.
That said, I can see warlocks getting this for specific raid situations for its great synergy with Nightfall, and two new abilities: Eradication and Haunt. Atrocity can be used to instantaneously DoT up a group of adds tanked by a Paladin, while you nuke the boss tanked by another toon.
Eradication procs off Corruption, Curse of Agony or Siphon Life to give you a very nice spell haste buff. Haunt is an interesting new spell that behaves like a chained DoT, hitting up to three targets afflicted by Corruption before returning to heal the Warlock.
Needless to say, Atrocity is deliciously evil in PvP, even on its own merits. Imagine landing a Corruption on all opponents in a battleground bottleneck and proccing instant and hasted shadow bolts with both Nightfall and Eradication. Remember to laugh in the ensuing carnage.
At the top end of the Demonology tree is Metamorphosis - an ability rich with fun roleplaying and PvP possibilities. With a 5-minute cooldown and a 45-second duration, your raid or party leader is very unlikely to want you to tank anything, no matter how cool you may look in demon form. And that's assuming that 360% of your cloth armor rating is good enough to tank anything. It might come in useful when some fellow clothie gets unwanted attention from a stray mob, but this ability is situational at best in PvE.
Metamorphosis in PvP might mean that warlocks have a greater fighting chance against melee classes like warriors and rogues. Switching to demon form has a powerful reset effect, since it pops you back up to full health and mana of the demon. With no further details of the "demonic abilities", it's hard to say what DPS potential warlocks have as demons. Another unresolved question is how much health and mana will we have when we return to normal form? If "normal" health and mana means full bars, it means that we get two resets! This makes a full demonology Warlock very durable in PvP indeed. I'm just hoping that Blizzard will use a cooler demon model (like Leotheras' demon form, above), instead of the boring dreadlord model.
We come to Destruction's Decimate, that turns our next spell into a potential "I Win" button - ignoring all resistances, absorption, and immunity mechanics - at the cost of not having access to the school of the Decimated spell for 3 seconds. Any bets that the candidate for Decimate will be a nuke from the destro school? This ability may breathe new life into Soul Fire, a spell that is probably not even on the tool bars of many warlocks currently.
The PvP implications of this finisher ability is immense, as the "bubble" ability of some classes like paladins and mages would no longer be entirely safe. Decimate can also be combo-ed with the Druid Cyclone with devastating effect.
PvE-wise, Decimate is certainly less useful. A Decimated nuke could penetrate the reflective shields put up by some mobs, but the question is: then what? I am filing Decimate under PvP, period.
DoTs and nukes
There is generally increased interaction between our DoTs and nukes. We've seen one such talent already in Eradication above, with DoTs proccing spell haste. At tier 10 of the Affliction and Destruction tree respectively, Everlasting Affliction and Eternal Flames both give nukes the ability to refresh DoTs that are already on the target.
Besides more damage for Corruption, Siphon Life and Seed of Corruption, five points in Everlasting Affliction gives a 100% chance of reseting the duration of Corruption with Drain Life or Shadow Bolt. With Corruption ticking only every 3 seconds, the constant refresh effect of this talent may result in Corruption hardly ticking if we follow up the DoT with 2.5-second shadow bolts!
For long fights, affliction locks could probably enjoy never having to refresh Corruption. In short fights where nukes are more important, the same DoT could be dropped from the spell rotation altogether.
On the other hand, Eternal Flames - the old Bangles' tune comes to mind - seem somewhat confused. It auto-refreshes Immolate with Searing Pain and Incinerate, while buffing the critical strike damage of destruction spells at the same time.
Unfortunately the auto-refresh effect here actually works against the damage potential of the hybrid nuke/DoT Immolate, especially one that has been buffed by Improved Immolate. Warlocks want both the nuke and DoT components of the spell. I can see many warlocks actually avoiding the auto-refresh effect entirely by sticking to shadow bolts between Immolates.
Shadow and fire, or smoke and mirrors?
The new talents in the Destruction tree, at first glance, seem to be geared towards improving the synergy between the shadow and fire schools of magic.
Molten Core at Tier 2 gives shadow nukes and DoTs a chance to increase the damage of fire spells by 10% for a small window of 6 seconds. Torture can proc an instant Immolate or Searing Pain off shadow bolt crits.
Looking closer, however, reveals that they are designed with PvP (can you say A.R.E.N.A.?) in mind. For PvE, these two talents have very little to offer in their current state. A temporary 10% damage buff to our off-school from Molten Core is inconsequential, considering how much other talents buff our shadow spells. With Torture, an instant Immolate will still trigger the 1.5-second global cooldown. Since Immolate has a normal cast time of 1.5 seconds for most warlocks with Bane, Torture offers nothing except the option of immolating on the move.
PvP warlocks will probably benefit more from these, especially for players who already use a wider selection of spells from both schools. The Molten Core proc may be frequent enough to average out as a small, passive buff to fire damage. Being able to cast Immolate or Searing Pain on the move could also be advantageous, although Torture is still underwhelming for its current depth at tier 9 of the Destruction tree.
In the next part of this article, I'll be wrapping up our peek into the future by looking at our newly empowered friends, the importance of keeping our Spirit up and comparing the talent trees. In the meantime, keep on dishing out death and destruction!
V'Ming still spends his time laughing ominously, but in the hallways of Tempest Keep and depths of Serpentshrine Caverns now.