It is awful; slowly but surely more and more DKs are switching to Unholy. And if you are looking to find out how useless Frost is you only have to give Black Furnace a try in Heroic. I will probably re-talent some stuff and try again as Frost there but at the moment it is really an extremely sub-optimal spec. If by next week NP and BoS will not make Frost competitive enough I will either respec or call it a day.