This really isn't directed at the raid tank, this is for 5 mans and the unwashed masses. What I think Blizz is seeing, is that as you increase the stats that increase the dps to deal with the ever increasing mob hp, the average tank in a 5 man isn't keeping up with threat. Overgeared dps v. new tank and new tank is getting shit on. Maybe they could have just tweaked the threat modifiers, but why use a crow bar to open a door when dynomite is so much more effective.
In the end, I think it will turn out to be much ado about nothing. The game goes on and to keep the franchise going, they need to appeal to the majority.