There's nothing wrong with DK tanks at all. I was tempted to go that route because they actually seemed more survivable than paladin tanks at a lot of things, and paladin tanks were actually designed around the idea that they NEED to take damage so they could get mana back from heals. However, I didn't want to invest too heavily into a class that was still new enough to the game that major changes were more likely than any other class. That's just me being probably a little overly cautious on my choice. DK survivablility wasn't even a concern in my choice.

But I'm definitely liking every single change they made to the tankadin spec in the last patch; everything got just a tiny bit easier. Increased mana regen on a blue rage bar tank makes a big difference.