Originally Posted by
Tanthalas
You do realise, that tanks do considerable amount of dps nowadays, so by swapping tank for dps you gain what? - 10-15k raid dps? It's a bit more on madness (only the number, not the percentage of damage) due to fight mechanics, but you can safely ignore it.
Also don't forget you'll have to deal with a last platform and 2 tanks are more convenient there. Besides, tank brings raid cd to survive through tentacles/bolt/harsh aoe on last platform. One-tanking is just not worth it.