There's some eye candy to avalon. In fact, I've seen a few things that look pretty fantastic. Smooth gradient shadows, two-and-a-half-d layering effects, liberal use of rounded edges, large san-serif type... It almost looks like... Mac OS X!
The applications that I saw at conviat.com are a particular theme for Avalon, fine, but it makes me happy that Avalon is capable of that sort of visual feel. I use Stardock Object Desktop to skin my tablet pc, which makes the look acceptable, but there's a hell of a performance cost. Now, if Longhorn actually builds in skinnability at the very lowest level, and I can actually skin my environment with no noticeable performance overhead, well, that might be a system I could work with.
As it is, yes, I'll say it right here and out loud: I choose to use my 15" Mac PowerBook G4 867 MHz over my 1.5 GHz/1 gb ram tablet PC and my 2.2 GHz giant dell laptop with a 1600x1200 screen because... it's more pleasant. It's just more pleasant to use the mac. It doesn't have to always be that way. If I joined the Avalon team, I could help make Avalon more pleasant, and I could help improve the user experience of the largest segment of personal computer users in the world. I think that could get me out of bed in the morning and staying late at night.