There is lots of hype about the semantic web 3.0. There are many things involved in the semantic web from video to search web 3.0 is making interacting with the web more like interacting with a person. I spoke to Barney Pell, the CEO of Powerset, and he said that semantic search is more like talking to a person because it understands the placement of adjectives, nouns and verbs.
Nova Spivack is the CEO of Radar Networks and they are developing the semantic web. They are very secretive about what they are doing, but everyone (including the NY Times) says it is going to revolutionize the Internet.