there are times where multiple iterations of how a set will look in the game are made, based on the original concept piece. In this case though, we felt there po wow to be such a gap in quality that we went back to the drawing board and came up with an entirely new piece of concept art, scrapping the original concept and in-game art done for death knights.
Well, I can say the new concept art is done and the set is close to being ready for image captures. I've not seen either, but I've heard very good things. :)