While they've telegraphed this before, it's further confirmation that they really do mean to return healing more to the vanilla-WoW style -- where good healing required not just quick reflexes, but also constant mindfulness of mana efficiency, cooperation with other healers in not overlapping, and avoidance of overhealing.
The current style of play is something that burned me out on healing for a good chunk of this expansion. The twitchy, 100% to 0% in 3s type of fights are exciting, but it gets to the point where there is almost no fun factor involved as you don't see anything but the healing grid until a fight is on farm.
It's to the point where you can't even use certain abilities (like greater heal or divine hymn) without giving people a heads up because if you stand still and channel or wait 2.5s to cast a heal then people start dying. I think a return to the mana regen mini-game is a small price to pay for being able to look at the ground without worrying about whether someone is going to die in the 2s you are looking away from the healing UI. So in a way, I'm looking forward to being able to use some of my current abilities as well in the expac.
As far as the new healing abilities go, I think if they set this up so that both holy and discipline can use the "chakra" buff, what should happen is that holy can be a decent tank healer in a stress situation, unlike now where flash is too weak and greater is too slow, and discipline will be a full time tank and able to help with the raid heals in a stress situation. I'm not that enthused about the "repeat three times" method of turning the ability on, but if holy nova is something that procs the AoE buff, then it shouldn't be that annoying.
Leap of Faith sounds fun, but it's hard to say whether it would be useful in a raid. They can't make it too useful or they get to where it is required to have X number of priests. I still wish they would fix lightwell or remove it, though it's kind of silly to be obsessed over one spell. Maybe have it be like a lightbomb where you just drop it into a zone and it does an AoE type heal repeatedly until it runs out of charges. Anything is more fun than this "bandage-well" ability.
One other thing I forgot to add is that the five extra talent points could open up soul warding as a hybrid holy spec. Which, while less effective than disc, could add "raid-bubbling" to Holy's toolkit. Something I'm looking forward to playing around with anyway.