I could easily see this seeing play in most control shaman decks. Definitely going to try it in my N'zoth shaman, and it's even made freeze shaman look pretty good. Maybe freeze could even be tier 2 this expansion.
Seems strong if you can fully leverage it. Against a 1 or 2 minion board, it's pretty weak. I'm not excited to put it into a deck, but it'll be an exciting and interesting card to work with when you get it randomly.
The fact that they need 3 minions in the proper spots for this to be good is troubling. The more people use this, the more people wise up and place their minions unfavorably to play around this, and then it's really weak even if you hit three things.