Haste: go for 2017 for now (assuming you don't have the talent that grants a passive 5% haste). Its kinda surprising that this expansion didn't raise the haste cap by much. I mean I know it was 913 for the first haste cap at 85, but I always went for the second cap of 2002. Anyway, level 90 haste should be 2017.
Spirit: It cannot be said enough: regen is our most important thing this expansion, and spirit is our primary regen stat since int no longer scales our mana pool. I am aiming for 9K spirit, but currently only have around 5,400 unbuffed (gonna do my first MGV tomorrow!). Never reforge out of spirit and always reforge into spirit for pieces that don't have any. Also, always gem for spirit.
Mastery: Our next important stat. Always get as much as you can get. There is no such thing as too much mastery.
Crit is always good too, but should not be our main focus right now. Get it where you can, and don't worry when you can't. Mastery is where its at for secondary stats (I consider spirit a primary stat, but it kinda is a secondary stat isn't it?)
I hope this info helps some.
Here is a link to my armory. I am one of the lead healers for my guild, but by no means are we hardcore. That doesn't mean I don't know what I am talking about though 8P.
http://us.battle.net/wow/en/characte...ikara/advanced