Open Calais - semantic web's first serious analysis engine

Reuters top-down metadata generation Calais service is now open for anyone to use (commercial and non-commercial). According to their FAQ:

The Calais initiative seeks to help make all the worlds content more accessible, interoperable and valuable via the automated generation of rich semantic metadata, the incorporation of user defined metadata, the transportation of those metadata resources throughout the content ecosystem and the extension of it’s capabilities by user-contributed components.

However, this is about more than just tagging and sets the stage nicely for the first serious analysis engine ala Semantic Web. Plus, it complements the recent Google Social Graph efforts built on XFN / FOAF via “bottom-up” metadata transport features.