Well it only took them 1 expansion to even try to make dk's fit the whole slow steady juggernaught but here is a first glimpse
"Death's Advance: For 10 sec, you cannot be slowed below 100% of normal speed, you resist forced movement effects by 80%, and you are immune to external knockbacks. Passive: You cannot be slowed below 70% of normal speed. 30 second cooldown"
Yes it will get neutered before it even hits retail but at least its there i guess,that also probably means that the knockback immunity from pof will get stripped
source:
http://www.wowhead.com/news=275396/b...the-demo-floor