Not only will we be viable Mr. Lightning, we will be just as wanted as a Warrior, Dreadknight or those sniveling Paladins.
/sneer
As to the OP, you may have finally stumbled upon a game where the best tank is not necessarily the one with the most armor and health. And for that I rejoice. We needed something intelligent in a game, and I believe we got one.
I plan on being a very intelligence-based tank, and watch for me in game cuz I'll be making waves.
-Eclipse