Okay.... so what archetype are they going for in Shaman? They add all of these new cards that push different archetypes in classes like Priest that are already really strong but they add cards like this that probably won't see play because they don't really fit in anywhere in the meta. This card just isn't good enough to see play as a 1 mana card.
EDIT: OHHH I read it wrong. This card could actually be very very very good mainly because one of the biggest downfalls with cards that evolve others is that sometimes you'll downgrade or get things like Doomsayer. This card serves as a safeguard after you use an evolve and get a 6 mana 1/1 or a poorly statted card. It also allows you to roll for answers when you need them. Maybe you're looking for a taunt to extend the game and you don't have any in your hand. This card could possibly evolve one of your other cards into a taunt minion. Regardless, I would on second thought rate this card as "Playable". I definitely don't think it's too powerful because evolve as a mechanic isn't exactly that strong due to its randomness, but definitely playable in some Shaman decks.
I wouldnt say if this is playable or not, but i would just say Evolve is an annoying mechanic to deal with. Also can you make up your mind Blizzard? last set you made "freeze shaman" for some reason and now for this Set you gave us 3 totem Cards and now you gave us this Random Card. If youre gonna make a sense, have it so you can make it clear for everyone what class archetypes are going towards.
Sign, I know this card will be played a lot, it;s just plain obvious, but
Jeesus, how I hate this randomness the devs put into shaman. Why can't we have normal control cards or something (not necessarily for control if you wish) strong on its own without having the word "random" in it...