Marissa Mayer, in a report on Search Engine Land last week stated that new search option features were introduced and designed to eliminate inconsistency in how Google presented search results.
"Although the Semantic Web (SW) is still very much in its infancy, there is already a lot of data out there which conforms to the proposed SW standards (e.g. RDF and OWL). Small vertical vocabularies and ontologies have emerged, and the community of people using these is growing daily.... "