I believe he mentioned Priest is next because of all the discussion it caused.
I would consider Warlock one of the weaker classes, but this was interesting to read nonetheless. I agree that nothing in DoW screams Warlock. This, I believe, will keep Warlock underdrafted. There are several classes with cards that you can pick up any card and have at least a decent build. Warlock takes patience, luck, and maybe even some premeditation. This is not to say there are not good Warlock cards. Brad has pointed out the best of them, but most of them push you into other classes.