is there a web 2.0 aesthetic?

This week's reading of Web 2.0: Mistaking the Forest for the Trees? by Dave Rogers raised more questions than it answered for me about web 2.0. I keep wondering if there's a visual style definitively associated with web 2.0.

I've probably read 15-20 articles about it, and I'm still not clear on what web 2.0 is. User-driven--I get that; Amazon, Google, YouTube MySpace as primary examples--ok; encompassing web-based services; yes. But it seems to be a term bandied about by just about anybody on the hi-tech wagon and used in a multitude of ways.

Tim Reilly, inventor of the term (according to the very web 2.0 Wikipedia site) currently defines it this way:

"Web 2.0 is the business revolution in the computer industry caused by the move to the internet as platform, and an attempt to understand the rules for success on that new platform. Chief among those rules is this: Build applications that harness network effects to get better the more people use them.". [3]

Hmm. . . sounds pretty open-ended and vague.