It seems very weak to me. The death rattle is great, but its a 4 cost weapon that only has 2 damage, and takes 4 turns to break. One of the big problems that Shaman has is that they're a weapon class with no self-healing. Rogue has the same problem, which is why Rogue decks center around putting the enemy away quickly.
Quite frankly, the only way to turn things around for shaman is to print some class cards that are OP as fuck. And I doubt that will ever happen. Shaman is a design failure. I wouldn't say they need a complete overhaul, but they definitely need more than a few small changes.