Web 2.0 Expo is a global annual gathering of technical, design, marketing, and business professionals who are building the next generation web. Web 2.0 Expo features the most innovative and successful Internet industry figures and companies providing attendees with examples of business models, development paradigms, and design strategies to enable mainstream businesses and new arrivals to the Web 2.0 world to take advantage of this new generation of services and opportunities. Web 2.0 Expo is co-produced by O'Reilly Media and TechWeb."
You may want to check out Tim O'Reilly's presentation. He coined the Web 2.0 term and discusses the core of Web 2.0 and some deep trends:
The first one is that the Internet really is becoming the platform, a global platform for everything, everything connected, and the nature of that platform is this amazing tool for harnessing collective intelligence. It's not just about participation. It's about literally we are building a platform to make the world smarter, to make businesses smarter, to make ourselves smarter. This is an amazing revolution in human augmentation. We're at a turning point akin to literacy, or the formation of cities. This is a huge change in the way the world works.
The home page for the conference can be found on the O'Reilly site and is well worth perusing.