Are tanks pointless?

[rodos]

Another way a designer could go with this is to allow any class to tank by making stamina a choice again, and handing out a lot more external damage reduction abilities. Things like HoSac, Pain Suppression, PW:S, Intervene, etc.

So, your party of 4 dps, 1 heals decides that Pauline the Paladin is going to tank this fight because it's mostly melee and she has plate and can throw on a shield (even though she's ret spec). The healers and the other dps focus their efforts on helping her reduce the damage she takes with CC and with spells and abilities that mitigate or spread out damage.

Next fight, Wally the Warlock tanks. He has a high stam set, and some abilities to help him take less damage from shadow magic. He can also use his pet to soak a bit. Again, the heals and dps do what they need to do to focus agro on Wally, mitigate the damage he takes, and stop him from being dead.

Unfortunately, this design would run completely counter to what Blizzard are trying to achieve -- letting a couple of experienced players carry the rest through random dungeons (we all know these threat changes were not made with raiding in mind). Spreading responsibility around in 5-man PuGs is not a recipe for success.