I agree too with...some things said by different people. x'D

Giving each tank specific strenghts and weaknesses really would add some diversity to the game and would also work great with a fourth tank. (I am expecting Viking, using a greathammer to become the next tank btw)
SE could also scale the tanks just like the dds. From high def/utility and low dps to high dps and low def/utility. (scrapping tank stances would be usefull for this)

Or with the introduction of a fourth tank they could declare two tanks as defensive tanks (PLD and DRK) and the other two to dmg tanks (WAR and possbly VKG).

Anyways, my predicts are a small PLD dmg nerf, maybe a small WAR dmg buff and a overall adjustement of DRK.