Not that good, if you think about it. Unless you developed decent board to trade and want to retake control then it's just maybe sometimes on the verge of power to old Innervate. This itself costs one, so in order to get at least 2 mana crystals you need to kill off 3 minions (probably trade twice).
This isn't ramp in the same sense that we've seen since it won't really enable combos. What it does though, is it allows for you to play a more token-based druid and bump up into some of the big threats or bigger plays. I think this is one of the coolest cards I've seen yet and I'm glad it doesn't help enable all the ludicrous OTKs and deck swaps that druid can do already.
I'm not really sure how good this is. It looks like a nice tempo gain in a token deck fighting for board, but it will then need to reload the board. In slower decks, it doesn't seem that good. Maybe there are some crazy combos that can be pulled off, but I'm not aware of them.