I've read alot on the forums and on different faqs and it seems most of the well known druids and people that know most about the class seem to want to have as much healing and mp/5 as possible.
It seems that most of the end game druids would prefer these stats over stacking spirit even though most other classes seem to think this is what druids are made to do (stack spirit)
As a tree druid that raids in hyjal and about to move into BT I spend very little time out of the 5 second rule which is the only spot where spirit really helps on ur mana regeneration, which is why it seems that mp/5 is far superior.
Obviously the tree of life aura helps healing from everyone else, but we have two resto druids and im not usually in the tanks group. The other resto druid is going with the spirit stacking type of build and always has to use his/her own innervate while i can give mine to a priest and still come no where close to running out of mana.
Any one else's opinion on the topic is much appreciated.