Everyone will have different opinions on this, and the expansion is too new for us to have all of the facts just yet. What I can say with 100% certainty is that Weapon Damage and Mind are absolute top priority, and not a single healer alive will debate that. Spell Speed is better on white mage than it is on the other 2 healers, because we are a HoT class. Crit is most useful on a scholar, but its not bad.

My personal opinion for White Mage is: Weapon Damage, Mind, Spell Speed, Determination, Crit.
I don't care about Piety because its just going to be there or it isnt. A good healer will learn to manage either way, and the difference it makes is quite minimal.
I'm at i185 and still have nearly 13k mana with my regen ticks sitting around 1100 each and around 1400 on a warrior.