That's a really neat design document - when you're talking about animations in multi-player, do you mean some sort of frame buffering or delay solution to synchronise gameplay over latency? I assume all of the animation is being managed client-side, as opposed to host-side. Netcode is kind of interesting.
Music can be really important, but from gamer playing habits (or what I've observed, at least), a majority of players mute in-game music and play their own, or use VOIP (especially in multiplayer).
Do you see any large-name titles coming out this Xmas season that might interfere with the sales of AVWW2? A repeat of what I've seen you call the Diablo 3 effect might not be nice.
edit: Weird request: I have a weird fondness for placeholder artwork. Got any you can share?