I will admit I discounted lifebloom during the PTR because of the heavy cost hit and all the cries of the sky falling made me overlook one key thing they did to Lifebloom.
It refunds mana upon bloom. This is significant since they reduced our OFSR regen. It accounted for 15 percent of my overall mana gain last night in our 10 man, and probably would have been more had I not figured it out halfway through the night.
I recently learned that Nourish is only affected by 1 stack of Lifebloom, so rolling it still doesn't work as well anymore, but keeping it going on a tank (or whomever your constant damage soaker is) and then tossing it around to say, folks who are going to be hit by a Gravity Bomb seems to work out nicely. And, if I let it drop on the tank for whatever reason (like when I need the burst heal) that's more mana gain, since the return is higher with more stacks.
It works out that if you throw on stack on a player, the difference in the cost ends up being cheaper than it was pre 3.1. That's with the 2p t7 bonus.
I haven't seen mana issues on 10 man too much. I think I used a couple pots and Innervated a couple times the whole night (both times were after a battle rez). Helped that I had the resto shaman in my group for the mana totem. 25 man, it's too hard to gauge yet though I imagine it will be a chore to keep the blue bar from going to zero the more we progress.
I am at a difficult spot now. I'd like to drop the mana restore meta gem in my helm in favor of the spell power/int one, but the gem also accounted for around 15 percent mana gain.
With the new Nourish set up, I opted to add a little more haste in my gear and switched my trinkets. Before I was using the Spirit-World Glass and the Majestic Dragon Figuring, both of which added spirit boosts. These worked out well pre Uldar because of the high regen I had and the utility to toss (glyphed)Innervates to others while still getting a benefit.
After some mediocre testing in Dalaran with Embrace of the Spider (98 spellpower, chance to gain 505 haste) and The Egg of Mortal Essence (same stats) I can keep a constant flow of extra haste to boost Nourish. They also can proc at the same time (Hello 1356/41% haste)... Yum.
I may drop these later for the 100 spirit 48 reduction in spell cost trinket out of 10 man Uldar, but in the meantime, I am liking the set up I have.