It's hard to go to an MR conference these days without at least one presentation about Web 2.0. Everyone seems to agree that MR needs to find a way to use user-generated content that is the staple of Web 2.0 but the industry continues to struggle with how best to do that. For some examples of how MR is struggling with this have a look at this post at Customer Listening. Before you do that you might want to check out a few links to some videos that may help you understand what the fuss is all about.
First up is Tim O'Reilly who is generally credited with coining the term Web 2.0. O'Reilly's explanation is about as succinct as you can get. For a more detailed explanation check out this video from U Tech Tips. Finally, there is what pretty much everyone I know views as the coolest thing yet to capture what Web 2.0 is all about. If you haven't seen The Machine is Us/ing Us you need to.