Right above Monks I would say.
Anyway what bugs me is I thought as a DK we were trading mobility for damage. But now I don't see the reason to be a DK over, say, a DH.
Also, I won't matter anyway. Blizzard will surely keep making changes to tanks on heroic week so I'm not sure if I want to gamble my choice of which class to play because hell, it might end up being dead last or the best tank in the game.