I am really grateful to the Syscon folks for creating this interview:
http://tv.sys-con.com/read/235922.htm
The gist is about the Web 2.0 but with some actual depth added to the concept. The ideas started during a blog exchange with Tim Oreilly. Despite the fact that the name "Web 2.0" is perhaps suboptimal, the "thing" that people have come to link to the term does exist. Problem is (of course) that the "thing" is undefined. Accordingly, everybody thinks it is something a little bit different.
The interview discusses some possibilities for creating a set of reusable architectural patterns using the Mackenzie-Nickull Architectural Patterns Metamodel to distill out the differences in Tim Oreilly's examples of Web 1.0 and Web 2.0. This would by far be the most concrete definition.
Dion Hinchliffe recently published an example of some of the Web 2.0 Patterns I have been working on. Matt Mackenzie, who is always thinking beyond the edge, also has some interesting thoughts on the subject of Web 2.0.