I had a lot of trouble healing on my priest at first. The change in how we heal (I'm Holy all the way.../hiss to disc) was difficult but then after I got used to the change my mana was suffering. It only got better when my gear got better and my mana pool hit around 80k unbuffed. Said this a couple times but this is how it happened for me. With this new content of course healers of all types will go oom or have a hard time if everyone else isnt doing their job with cooldowns and CC. This expansion requires your team to actually be a team. I've come to really enjoy healing now...it's callenging no matter how many times I do something. BTW priests...you hit 85 and get that nice new buff reducing your instant cast spells

i find myself casting a ton of instants and 'heal'. Raiding wise...whew..you need a strong heal team all around...one person cant carry anymore with the way mana is eaten now. If anyone's interested in holy healing on a priest, I'd be happy to share my 'rotation'...just let me know.