Jeremy Zawodny's doing a nice job of summarizing Web 2.0. One talk that interested me was Joe "not your father's company" Kraus demoing JotSpot, a "new generation Wiki that makes it easier to add structured data to the system in addition to pulling in external data via RSS, Web Services, and so on." Check out the advanced tour for a quick intro to what you can do with structured data in a wiki. Looks pretty darn cool.