There's a great discussion of Web 2.0 versus Semantic Web that I've been following.
I'm kind of happy to see a discussion like this happening and to see Tim O'Reilly wrapp up with this kind of thought: "Metaweb strikes me as an evolution because it's a kind of next gen hybrid between semweb and web 2.0.".
This is shedding some light for me in the debate I was having recently about why Semantic Web does not seem to be progressing as we all like it to (although there's good signs that it might after all). If the two main arguments of why would be inner comlexity versus market interests, I'm leaning to think that complexity is a big part of it although of course there could be a combination of both.
Anyway, when I had to choose one conference to attend this April/May around this subjects, I decided I'd go to WWW instead of a Web 2.0 Conference. It was mostly a curiosity and cost/benefit based decision, but after seeing Mark Birbeck's arguments as well as James Hendler's I'm pretty happy I did. Can't wait to be there embedded on the semantic world.