While Web 3.0 has been talked about for some time, there has been increasing and ongoing discussion as to how it should best be defined and what the foundational characteristics of the technology are or will be. The reality is, however, that while there are attempts at clear definitions, the ideas and concepts continue to evolve as users make sense of where things are going.
http://thejournal.com/articles/2010/02/03/web-3.0-and-its-relevance-for-instruction.aspx