Since it appaears that you have to aim the bow, with everyone likely bouncing around in pvp, will the bow be less viable than the easier to aim builds like melee?

Actually, most people have been saying that ranged combat is more viable than melee combat in pvp, at least in groups.

I can agree. I was in PvP last night in a small group and we managed to get through with our bows and controlled most of the map by the end.