These preview notes made me laugh. To the masses, these 'highlights' can probably give cause for celebration, but in reality, to many who understand their class roles well enough to see through the smokescreen, many of these changes are quite lackluster.
The biggest prize in these notes for Priests is the self cast Penance. Unfortunately, selfcast Penance is far more of a PvP buff than a PvE buff. Yes, PvE'rs, if you are in a bad situation where you have to heal yourself right now, Penance can solve that issue. However, the bigger issue in that situation is letting yourself get that low. Positioning and communication can usually prevent that bad situation from even happening and even if it does, Binding Heal is often a better self heal since you know that the tank is also taking damage.
Discipline is definitely getting a huge boost with Power Word: Barrier, aka AOE PW: Shield. Talent synergy-wise, I hope that Rapture works on PW: B. That could be some sick mana regen on a fight like Thaddius, Malygos or Sarth with Drakes up. If Blizz ever gets around to fixing Reflective Shield and linked it to PW: B along with Borrowed Time/Improved PW: Shield, that would be class changing. Chances are, it won't synergize with any other talents a la Divine Aegis. But that's okay, too.
Looking at the possible utility of PW: B from a PvP perspective, it seems like a 3's and 5's tool, especially with quick dps teams where burst prevention is often worth more than healing. PW: B's performance will probably be lackluster in 2's, but we'll see what the details of the spell are before we make that final judgement. I do foresee that the mana cost will be extremely high, as it should have the same final outcome as a Prayer of Healing or two since PoH is spammable.
It's about time that DS became baseline. Having to waste talent points on that BS was a joke.
One thing I am quite amused about with the other changes is that Prayer of Healing will be changed to behave just like the old CoH because it will be Group Based with no cooldown. With enough Haste, Holy Priests could viably just spam AOE heals, which would, again, defeat the intentions behind whole CoH nerf. The silly thing about the PoH change is that Blizz recently said that they wanted to eventually get rid of the Groups within a Raid and this change to PoH essentially forces additional group shifting. Think: healing melee on Sapphiron would make it easier if they're all in the same group. Same thing with KT's Ice Tombs. If anyone ever comes up with an 'on the fly group switching' tool to rapidly switch holy priests around to groups that need aoe healing, the game will have reached a new low.
On the Holy end of things, the Serendipity change is kinda 'meh' as Holy Priests don't really cast Greater Heals anymore because of the glyphed Flash Heal efficiency. Of course, if there's something really wrong and you happen to have several seconds to cast a gHeal, I could see it work. Maybe Uludar will bring back bomb healing, but I see this talent change as just fluff. If there is a ton more healing to be done in future instances this could be a class changer as well, but one thing's for sure, we're going to need numbers to truly determine their end value.
As these are preliminary notes, I'm not holding my breath, but unless 3.1 raiding brings alot more AOE and raid damage, I probably won't be impressed.
But, I am happy that I will soon be able to cast Thorns while in Tree of Life form!