Just read something about the following project:
DBpedia.org is a community effort to extract structured information from Wikipedia and to make this information available on the Web. DBpedia allows you to ask sophisticated queries against Wikipedia and to link other datasets on the Web to Wikipedia data.
Instead of searching the full-text of Wikipedia, it allows you to execute SPARQL-Queries on the data. With “the data” i mean RDF-Data. Because the goal of the DBpedia-project is to create a whole bunch of structured data out of the Wikipedia-texts.
A little search interface can be found at http://dbpedia.org/search/.