Blizzard just made available a MOP talent calculatorTalent Calculator - Game - World of Warcraft
Of note is that you can also click on the 3 specializations and it gives a listing of what the available spells are.
General class changes: Shadow Ward is now Twilight Ward and it absorbs shadow or holy. Fel Armor has changed, now it just increases armor, stamina, and healing received, but it is now a passive vs. an actual spell. Curse of Enfeeblement combines Curse of Tongues and Curse of Weakness, decreasing physical damage and cast time by 30%. Tool tip says it is less effective on bosses. Nethermancy is a passive at level 50 that increases your int by 5%. New spell at 64 is Unending Resolve: 10% base mana cost, 3min cd, Reduces all dmg by 50% and prevents spell from being interrupted for 12 seconds. Dark Intent has changed, now it is a raidwide buff that increases spell power by 6% for 1 hour. New spell at 88 is Demonic Portal...it literally sounds like it's from the game Portal in that you create 2 portals and people who go in one come out the other. It has 5 charges, but charges regen at 1 charge per 15 seconds. The tooltip mentions it has a 70 yard range. Interesting spell.
Destruction: Bane of Agony, Bane of Doom, and Hellfire have been removed as available spells (they still get corruption, but no seed of corruption). Chaos bolt appears to be GONE. Infernal Embers boosts dmg of soulfire or conflag. Aftermath is now a base passive at 54, biggest change is now it makes it so rain of fire DOES NOT have to be channeled anymore and it stuns all enemies inside it for 2 seconds! It still makes conflag daze as well. Rain of Fire now also does bonus dmg vs. immolated targets. Fire and Brimstone at level 62 is different, now it says your next incinerate, immolate, conflag, or soulfire will hit all targets within 15 yards of your primary target and it notes that it is instant cast /w a 10s cd (I guess we see the use of this spell now, since RoF does bonus dmg vs. immolated targets). Bane of Havoc has been changed, it now lasts 15 seconds so that the next 4 single target spells cast will also hit the bane target, 2m cd. Backlash is now automatically given at 73. Emberstorm is given at 80 and has been changed so that it increases infernal ember benefit by 4% and each point of mastery increases bonus by 0.50%. New spell at 86 Destructive Influence: Each attack by your demon reduces cast time of your next soulfire by 0.1 seconds, stacking up to 40 times..
Demonology: Rain of Fire and all the fire single-target spells except Soulfire have been removed. Bane of Agony removed. Bane of Doom is now demo only. Metamorph is given at level 10. Demonic Fury tooltip indicates it increases your damage by 10%, which is modified by mastery (Shadow bolt, corruption, soul fire, and drain life build it up). Wild Imps at 32, base is 1 imp that casts 5 firebolts (each bolt yields 10 demonic fury), tooltip says # of imps and cost of cast increases based on amount of demonic fury you have built up. Immolation aura is now different, it turns Hellfire into a spell that costs demonic fury vs. mana, does not need to be channeled, and it does not damage you. Demonic Rebirth is a passive at 54 (instant resummon), you have a 20s window to cast and it has a 2m cd. Hand of Guldan is now a base spell. Decimation is a passive at 69, based on the tooltip is essentially a soulfire execute where if you cast a soulfire on a target below 25%, your soulfire is 2 seconds less to cast, but if it is over that amount, your next soulfire has double cast time for 30 seconds. Demonic Freedom at 73, heals demon and removes all CC. Shadow Flame appears to be demo only now. Master Demonologist is passive at 80, boosts dmg by you in meta form, demonic fury benefit, and demon dmg by 1%, each point of mastery increases by 0.1%. Carrion Swam, new passive at 86. If you cast shadowflame in meta form, shadowflame costs fury vs. mana and it knocks enemies away.
Affliction: No hellfire/RoF. No fire spells except soul fire. Unstable Affliction give at 10. Soulburn and drain soul appears to be affliction only now. Drain soul creates 1 shard per 4 seconds and drain soul still acts like an execute, where it's damage is doubled on targets below 25%. Soul burn changes: Health funnel instantly heals + reduces dmg, fear becomes death coil essentially (no healing), seed of corruption places corruption on all damaged targets from the seed explosion, demonic circle is more or less the same. Seed of Corruption is Affliction only (No more seed bombs for the other specs!). Bane of Agony is affliction only. Malefic Grasp at 42, it does dmg + makes your dots tick 100% faster. Nightfall procs now change Malefic grasp vs. shadowbolt (since SB changes into grasp). Improved Fear passive at 69, fear now also slows target by 30% for 5s after fear wears off. Soul swap is still in. Potent Afflictions, passive at 80, all periodic shadow dmg increased by 13%, each mastery point increases bonus by 1.63%.
Talents have changed since Blizzcon as well in some cases, most notably the level 60 tier (based on my memory of the panel).