Yeah I've been playing with this talent on the ptr,
Reckon it's worth picking up if you consider getting an OoC proc; wild growthing your group and having a chance to gain some mana back for nothing seems pretty nice, even your other healers will agree =P. I guess even if you don't get an OoC proc it's still something extra that your raid will like. Though the chance to proc might not be that high, think about how many proc's will occur in one fight.