How would it not work for PvP? It would allow you to cast while moving. It is easily dispellable / removed. Would allow you to keep moving with your healer so long as you weren't focused / dotted. If you were dotted, it would be up to your healer or even self dispels to remove them. It would greatly depend what kind of comp you were running with, but overall a possible and viable mechanic.
Please elaborate on how it would not work, instead of just saying it won't.