Web 2.0: Mistaking the Forest for the Trees?
Think of Web 2.0 as more of a concept than a person, place or thing and you'll find firmer ground. Even better, spend some quality time with O'Reilly's lengthy essay. Finally, keep in mind that the lion's share of Web 2.0 discussion is from a technological perspective; it hasn't yet filtered down to the information architecture, interaction design and similar discussion lists.
Rogers, Dave. GotoMedia (2006). Articles>Web Design>User Experience>Interaction Design