3.1.0 upcoming changes

Warlocks

Banish: Now has a 6-second PvP duration.
Curse of the Elements (Rank 5): Increased to 13% spell damage, up from 10%.
Curse of Recklessness has been removed.
Curse of Weakness: Now also reduces the armor of the target by 5%.
Drain Soul: Each time Drain Soul deals damage to a target which can grant experience, it now has a chance to generate a Soul Shard.
Enslave Demon: Spell haste penalty reduced by 10%. Melee haste penalty reduced by 10%.
Doomguard: Cooldown reduced to 30 minutes, down from 60 minutes. Damage reduced approximately 30%, and health reduced approximately 30%.
Warlocks now innately have an increased 10% spell hit chance on the Enslave Demon spell.
Fire Shield (Imp): You can now cast this ability on raid members, rather than party members.
Ritual of Summoning: The summoning of the initial portal is now instant cast, down from 5 seconds.
Soul Shard: This item now has a maximum count of 32 in inventory.
Voidwalker: The health bonus on this pet has been reduced from 60% to 10%.
Talents


Affliction
Eradication: Whenever you deal damage with Corruption, you have a 6% chance to gain the Eradication effect. The Eradication effect increases your spell casting speed by 6/12/20% for 10 seconds. Internal cooldown removed.
Haunt: Now only increases your shadow damage-over-time spells on the target.
Malediction: No longer increases the effect of Curse of the Elements, but now also increases the periodic critical strike chance of your Corruption and Unstable Affliction spells by 3/6/9%.
Pandemic: This talent has been reduced to a 1-point talent. Now grants your Corruption and Unstable Affliction the capability to critically hit.
Shadow Embrace: Now only increases the damage done by your shadow damage periodic spells.
Siphon Life: The Siphon Life spell has been removed. Siphon Life now causes your Corruption spell to instantly heal you for 40% of the damage done. In addition, the damage done by your Corruption, Seed of Corruption and Unstable Affliction damage-over-time effects is increased by 5%.
Soul Siphon redesigned: Increases the amount drained by your Drain Life and Drain Soul spells by an additional 3/6% for each of your Affliction effects on the target, up to a maximum of 9/18% additional effect.
Suppression: Now increases spell hit for all of your spells.
Unstable Affliction and Immolation are now in the same exclusive category (both damage- over- time effects cannot be present at the same time by the same caster on a target).


Demonology
Demonic Empathy has been removed.
Demonic Empowerment: This talent now has a unique spell effect.
Demonic Sacrifice: This talent has been removed.
Fel Synergy has been moved to tier-1. No longer increases intellect, stamina and damage of your summoned demon.
Improved Enslave Demon talent removed.
Mana Feed: This talent is now a 1-point talent, down from 3 points. Now is the 21-point talent in Demonology, granting 100% mana return to your pet, up from 33/66/100%.
Master Conjuror: Increased from 15/30% up to 150/300%.
New Talent: Decimation: When you Shadowbolt or Incinerate a target that is at or below 35% health, your next Soulfire cast time is reduced by 30/60% and costs no shard. Lasts 10 seconds.
New Talent: Nemesis: Reduces the cooldown of your Demonic Empowerment, Metamorphosis, Soulstone and Fel Domination spells by 10/20/30%.


Destruction
Aftermath redesigned: Increases the periodic damage done by your Immolate by 3/6%, and your Conflagrate has a 50/100% chance to daze the target for 5 seconds.
Backlash has been moved up to tier-5, up from tier-7. Now requires Intensity (pre-requisite).
Cataclysm: Now reduces the mana cost of Destruction spells by 4/7/10%. No longer increases the chance to hit.
Conflagrate: Spell now works similar to Swiftmend, consuming an Immolate or Shadowflame effect on the target and dealing damage based on the strength of that effect. Reduced to a single rank.
Improved Immolate: Now increases the damage done by your Immolate by 10/20/30%, rather than just the direct damage.
Improved Shadow Bolt: Now increases the damage done by your Shadow Bolt spell by 1/2/3/4/5%, and causes your target to be vulnerable to spell damage, increasing spell critical strike chance against that target by 1/2/3/4/5%. Effect lasts 30 seconds.
Improved Soul Leech: Now has a 50/100% chance to proc Replenishment.
Molten Core: This talent has been moved to Demonology (tier-.
New Talent: Molten Skin: Reduces all damage taken by 2/4/6%.
Pyroclasm redesigned: Now increases your Shadow and Fire spell power by 2/4/6% when you critically hit with Searing Pain or Conflagrate. Lasts 10 seconds. Also moved down to tier-7 from tier-5.

What 3.1.0 means for warlocks is that Affliction is getting boned!

Currently the removal of Siphon Life, the moving of molten core to demonology(not to mention it a shared spell with UA), and the change to drain soul is being calculated as a 800 dps nerf.

3.1.0 does make the deep affliction rotation much simpiler. At the moment warlocks have to keep up Haunt(which refreshes Corruption), Curse of Agony, Siphon Life, Immolate, Unstable Affliction, and Drain Soul (while mob is 25% or under, spam Shadowbolts while dead time until then) to maximize dps. The 3.1.0 changes makes it so that Warlocks will only have to keep Haunt, CoA, and UA up, shadowbolt in dead periods.

This is rather annoying for two reason;

1.) The deep affliction rotation was a challenge and it was very easy to tell who was a moron and who knew how to play their class just by the dps they did with the tough rotation. I personally find the pre 3.1.0 rotation to be alot of fun.

2) The obvious 800dps nerf sucks, plain and simple.

With the current notes on the 3.1.0 patch it is currently looking like Demonology and Destruction will be the better specs to play in raid enviornments.

As always, things are still subject to change until the patch is actually released.