50 talents in three trees, 5 of them renamed or reworked since Classic.
Suppression5 ranks
Improved Corruption5 ranks
Improved Curse of Weakness3 ranks
Improved Drain Soul2 ranks
Improved Life Tap2 ranks
Soul Siphon5 ranks · was Improved Drain Life
Improved Bane of Agony3 ranks · was Improved Curse of Agony
Fel Concentration5 ranks
Amplify Curse1 rank
Grim Reach2 ranks
Nightfall2 ranks
Improved Drain Mana2 ranks
Siphon Life1 rank
Curse of Exhaustion1 rankImproved Curse of Exhaustion4 ranks
Shadow Mastery5 ranks
Dark Pact1 rank
Improved Healthstone2 ranks
Improved Imp3 ranks
Demonic Embrace5 ranks
Improved Health Funnel2 ranks
Improved Voidwalker3 ranks
Fel Vitality5 ranks · was Fel Intellect
Improved Sayaad3 ranks
Fel Domination1 rank
Fel Stamina5 ranks
Master Summoner2 ranks
Unholy Power5 ranks
Improved Subjugate Demon5 ranks
Demonic Sacrifice1 rank
Improved Firestone2 ranks
Master Demonologist5 ranks
Soul Link1 rank
Improved Spellstone2 ranks
Improved Shadow Bolt5 ranks
Cataclysm5 ranks
Bane5 ranks
Aftermath5 ranks
Improved Firebolt2 ranks
Improved Lash of Pain2 ranks
Devastation5 ranks
Shadowburn1 rank
Intensity2 ranks
Destructive Reach2 ranks
Agonizing Flames5 ranks · was Improved Searing Pain
Apocalypse2 ranks · was Pyroclasm
Improved Immolate5 ranks
Ruin1 rank
Emberstorm5 ranks
Conflagrate1 rankFrom the Forever beta client's own talent tables (build 1.60.1.69977). Talents marked "was" have a new name compared with Classic Era, so their effect has probably changed too. The beta can still change any of this.
Starting priorities, based on how Classic stats work. Forever is still in beta and Blizzard is changing stats, so treat these as a starting point. The upgrade checker lets you change the weights.