Although I am not a resto shaman (I spec ele) it seems that shamans have a great deal of difficulty in movement based fights that 15 seconds of "cast on the move" doesn't seem to solve and thus creates even more difficulties for healers that don't have Oh S**t buttons. Perhaps Blizz could alter Spirit Walkers Grace (through a resto talent or glyph) that treats it like Blade Flurry for combat rogues and allows shamans to toggle it on and off with a CD and a penalty of some sort such as increasing the mana cost, spells no longer benefit from haste, etc.

This would:
1) give shamans a unique mechanic and play style with no real duplication from other healing classes
2) substitute for a traditional cooldown (or it could be considered a throughput increase since there would be less interruptions to casting)
3) allow Blizz to tweak an already existing spell rather than create a new one

I really like spirit walkers grace and I wish that changes could be made to make it more viable as an actual CD. Or they could just give us back Spirit Link lol