The freedom to take your data away rather than controlling the rights to your source code might dominate the Web 3.0 meme. Hadoop! "I got a call from David Filo (co-founder of Yahoo!) last night saying Yahoo! is really behind this."
The main focus of the attention was the Doug Cutting and Eric Baldeschwieler talk.
The whole, shared nothing programming model is certainly infectious and it seems scarily appropriate for Semantic Web data (see some of the talk for more information). Yahoo's Hadoop research cluster is now apparently up to 2x1000 nodes.