With raid wide buffs, there is no need to have the traditional tank group. So who do you put in a tank group?
Well, in my opinion 25% of a SP DPS at 80 is going to be at least 500HPS - why would you not put that in MT group to make healers job easier?
Threat testing is, of course, impossible to discern outside of Beta runs. My tank friends assure me they are doing far far more TPS then before and expect to scale well. So I am going to assume we will not be even close to their threat.
If that is the case - why on earth would you not take it? ^_^