having the 4th as a tank is always nice. 4x ele shaman will instagib just about anything anyway. If you don't have a tank, instaces are going to [s]be a pain[/s] take a lot of creativity

In high end pvp, such as arenas, a second person playing a dedicated healer is pretty clutch. And even if you're doing world pvp or battlegrounds, how much more would that dedicated healer help you dominate. My biggest regret for my first team is not having a tank. I really wanted to do instances and anything else that needed armor better than cloth, and I just couldn't