Some discussion recently about the vision of the semantic web...
Tim Berners Lee features in The Times Online (http://technology.timesonline.co.uk/tol/news/tech_and_web/article3532832.ece) talking about the potential of the semantic web
Discussion on the BCS-KIDDM list referred to an earlier talk by Prof Ian Horrocks (http://www.epsg.org.uk/pub/needham2005/Horrocks_needham2005.pdf) which is a very readable intro to the concepts behind the semantic web and also refers to Manchester's work with Protege, including the pizza demo.
Yahoo have also been talking about semantic web, in particular its application in web searching (http://www.ysearchblog.com/archives/000527.html):
"In the coming weeks, we'll be releasing more detailed specifications that will describe our support of semantic web standards. Initially, we plan to support a number of microformats, including hCard, hCalendar, hReview, hAtom, and XFN. Yahoo! Search will work with the web community to evolve the vocabulary framework for embedding structured data. For starters, we plan to support vocabulary components from Dublin Core, Creative Commons, FOAF, GeoRSS, MediaRSS, and others based on feedback. And, we will support RDFa and eRDF markup to embed these into existing HTML pages. Finally, we are announcing support for the OpenSearch specification, with extensions for structured queries to deep web data sources."