Overall, I think that the new ideas for the talents are really interesting and cool. However, I am really disliking that some tiers will have a definite "better" choice for PvE, which is what Blizzard wanted to get away from. Granted, it's only barely in an Alpha state, so obviously things will change a lot in the coming months, but here are some of my initial thoughts as a Shadow Priest.
Tier 1 - The two new abilities, Void Tendrals and Psyfiends, are really neat ideas. I can't see them being much use for PvE, so I'll be going with the boring Psychic Scream, but I'm still loving them.
Tier 2 - As shadow, I can see myself using any of these a lot. Personally, I'll probably choose Body and Soul for most fights since it can be good in a PvE pinch, but the levitate talent is awesome and Phantasm is great for any movement speed reducing fight like H Saurfang was in ICC.
Tier 3 - Some big worries. 1. Divine Star seems holy-based. Can we use it in shadow form? 2. It seems like we're being forced to pick between a lot of DPS cooldowns. There will surely be a "best" if you're looking to min/max unless blizzard REALLY tries to balance them all, otherwise everyone will end up taking the same talent. 3. The wording of Archangel for shadowform makes me wonder if we will still have Dark Evangelism. 4. Surge of Darkness: "... cause your next Mind Blast to be instant cast and have no Shadow Orb cost" - will Mind Blast consume Shadow Orbs instead of using mana, like Holy Power for Paladins?
Tier 4 - I'm loving that these are personal-CD based. I really like that we'll be able to pick some sort of self-defensive ability based on our playstyle (personally, I'll probably take Angelic Bulwark since on-demand extra absorbs are awesome). My only issue is that of Desperate Prayer. It's a heal, so can we use it in Shadowform like Druids can use Renewal (Tier 2) in all shapeshift forms? This issue stuck out because we are still not able to use Gift of the Naaru in Shadowform even though that's not a priest-only spell.
Tier 5 - Again, it seems like we're being forced between a DPS cooldowns and an execute phase. There will most likely be a "better" choice between PI and Twist of Fate. Not cool. Granted, if it's as easy to change these as glyphs (as was promised), hopefully it won't be TOO much of an issue depending on the fight.
Tier 6 - LOVING that this Vampiric Dominance is a smart heal. Finally, no more wasted VE ticks. The Void Shift is also really interesting and I could see how that would be extremely useful in some fights in the past (plus, even more griefing if you so desire. Steal the a friend's health when you're low, bwahaha). Also, if Atonement is still present in our class after all of this hullabaloo, would it double dip from Vampiric Dominance?
Again, I'm not that fond of Tiers 3 and 5. I thought that they wanted to focus on non-DPS/HPS related playstyles for people wanting to min/max. But what are your thoughts for the new tiers?