It's impressive to be sure because it still takes a super-excellent player. However, the simple fact that something like this even possible with a DK in the first place is I think where the cause for concern lies.
This shows just WHY Blood DKs NEED a blasted nerf. -.-
Do this yourself.... then you are entitled to say this, but somehow i doubt you will get anywhere near close...
you will learn dk's are not simply facerollable to achieve results like this,
once you discover strategy, skill, and close to perfect timing... you will not scream nerf... unless maybe to nerf Moine ^^
This is why my guild prefers to have the blood dk over my pal tank for challenge modes.. seems balanced.
People thinking it is only the DK doing this and no skill from the player think think they can perform at Paragon/Method/Envy level if they themself played a DK ??
Maybe it also has something to do that this particular DK is in the top 3 guilds in the world which is 100% skill.