DK's have a 20 second cc immunity on a 1 minute cooldown at the moment due to a bug.
Here's to hoping it will be fixed soon.
Sadly, due to another bug, they can also use Death's Advance during this cc immunity so they can't be slowed either, while Frost Strike also does 50% additional damage.
We can only wait for fixes for them, as well as warriors, who are even more positively bugged.
Luckily, I think only these 2 classes have positive bugs, as I have not come across other classes with any major positive bugs.