I'm totally on board with the 4e concept of simplifying NPCs and monsters. I love the idea that a group of enemies can be described and be combat capable with only a few lines of stats. But when you get to villians, NPC or monster, I want more detail. While I don't care if his minions are paper-cutout thinly developed, the evil vampire or dragon or devil I want to have the same level of complexity as the players. To me this makes him more interesting to myself and the players.
Everything I've heard of these high level monsters so far they seem so simplified, reduced to a handful of mediocre attacks and one, maybe two special abilities.