I am doing 3 shaman right now but 4 locks and a priest would rock in pvp. I have a 70 lock thats sl/sl and he is a force in pvp. In arena we drain healers mana ftw and out last people. I couldnt imagine what a 4 lock 1 priest would do to healers mana x 5. Mana burn and drain would suck out there mana so fast it wouldnt be funny.

I would spec two locks sl/sl one for UA and one with felguard. Just thinking about the possibility of 4 locks and a priest make me want to try it some time.