Well, I am an experienced DK when it comes to Frost DW tanking, and I have always wondered about DW dps now that I am Blood two-hander tank. The thing is, I have been seeing alot of DK's on my NUB server go unholy DW without having any points in Blood. The spec they use looks like THIS. I myself have been looking at a Frost spec that makes sense to me, and have seen on fewer DK's, but better geared ones. That is THIS spec/glyphs.
My question for you guys is, which is better???
If Unholy, Why? And why in the first place does it work at all?!
If Frost, why?
Well ignoring the troll. Let's see if I understand your question correctly. Are you comparing Unholy 2h to Frost dw?
Unholy dw is pretty much dead these days, although I've seen some speculation that the next patch's massive haste buff will make unholy dw viable again (personally I wouldn't count on it).
Frost dw is currently a little behind the other builds for dps, but it's serviceable and if you lack an enhancement shaman it can work for your raid. Plus frost is inline for some buffs in the next patch (although the big one will only be apparent with an enhancement shaman - icy talons stacking with windfury).