Is there a real "need" for a tank? Granted I am only level 44, but so far the dungeons seem easier if the group does not have a tank. With 2 dps, a healer and a support (dps/healer), the group kills faster and the run generally goes smoother and faster.
Saying that I believe the issue is the lack of a true "tank". The only "taunt" available until the mid 30's is a rapture and it is nothing more than a joke. The ability is a single target damage over time, almost every pull in a dungeon is in big groups. The mechanics are set up so that when the tank engages all mobs he didn't hit runs straight to the healer or a dps that gets a hit in. ESO themselves said using puncture before the DoT has ended is just wasting the ability and does not add extra aggro.
That is why I think a tank isn't needed until they fixing "tanking". In a group with a tank everyone is expecting the tank to take the damage while they sit back and heal or dps. In a group without a tank everyone knows they are going to take damage and adjust accordingly.
Anyone else try dungeons without a tank?