Well, I don't have shaman myself, but i like them as my side-kick in arena, allthough we still need to improve lots of things.
The only negative point about shamans is their lack of CC, they don't have things like entangle or cyclone or fear. That''s why I think something like stasis trap would be lovely.
Let's say... Totem of Stasis Trap, which you will all remember from the old WC3 days. You can see when the shaman casts the totem, but it goes invisible after 2 sec, so it can be shot down,. It's only a 5 yard range to proc it.
It can be detected by hunters with flare, so it can be shot down from distance.
If you come close to it (5 yards) it will blow off and aoe stunn everything within 15 yards range, for 3 sec. (that's not alot, if you compare with charge or seed of corruption)
This way shamans can get away when they are struck on their position behind pilars or boxes. I realy think this will boost the gameplay with a lot of fun. And good and pro players will have the answers to counter it. Like watching CD come off with addons, you have 2sec to kill it before it turns in stealth. Hunters can still kill it with flare. AND offcourse you don't need to go close. After 15 sec the totem dissappears.
Let me know what you think, just discuss.