Shaman are getting a lot of love this expansion. What we know as a Shaman deck is going to change quite a bit. This card might be "bad" but it's the highest healing card in the game, and that's gotta count for something.
Compare this to Healbot:
Healbot:
5 Mana
8 Heal
3/3 Minion
Healing Wave:
3 Mana
7-14 Heal
2 Saved Mana can be used for:
- Totem Golem: 3/4
- Haunted Creeper: 3/4 worth of stats
- Sunfury Protector
- Zap-o-Matic
- Rockbiter or Lightning Bolt or Earthshock or Crackle
- Flametongue Totem
- etc
I don't know how you can say this is worse than Healbot when there are better 2 mana minions than the 3/3 Healbot?
Also the fact you can use this 2 turns sooner, which is sometimes necessary, and there are so many other 5 drops you want to play instead of Healbot, such as Loatheb or Belcher.
I can't see why you would want Healbot over this at all.
This healing also makes Weapons less dangerous for Shaman.