I was Arms until I hit 70, at which time I made the choice to re-spec protection, and learn tanking as we had no tanks in our guild. There is a need for all 3 talents in the game, must be why blizzard made it that way. I love having a dps warrior with me in groups. I take the punches, and they kill them quickly. A dps warrior can also off-tank in a pinch. My only advice to the dps warriors in a group with a prot tank, don't exceed the tanks threat, we have enough on our hands with the mobs and watching the healer. I won't be able to pull the aggro off a dps warrior, and do the rest as well, so I usually won't try. exceed tanks threat = death usually.