It's a 6% proc chance for both Elemental and Restoration, and it has a 4 second internal cooldown against players, so it doesn't cause unreasonable damage.
I suggest some tips for you:
1. You read up on a talent before you decide that it needs to be nerfed and;
2. You read up on the fact that it's not even useful in PvP, and any Shaman with half a brain wouldn't pick it anyway.
Cry for a nerf for Echo as much as you want, it really won't change anything. Besides, haven't you read the front page? It's being redesigned.