I don't think any other melee comes close. Most people focus on the snares and range closers, but there is a hell of a lot more, some of which have been mentioned but here's my list:

1. They can soak up damage like no other melee class. With AMS, IBF, and Vampiric blood (which will pop you to 50k hp in proper gear) your dk can survive being focused (since everyone goes straight for them).
2. Fear and sap immunity
3. Abomination's might and icy talons. Although I'm not completely sold on icy talons.
4. Hungering cold - another nice aoe cc. It's not the best, but it's better than the 1 terrible cc us shaman groups have
5. Best ranged interrupt you're going to get. A not so bad melee interrupt either