The founder of Wikipedia is teaming up with Amazon to create a search engine the competes head-to-head with Google and Yahoo. The new search engine is called Wikiasari. The idea behind the Wikisaria search engine is to to be driven by the same kind of community force that has been driving the Wikipedia.
I personally believe that both Google and Yahoo will be fighting back ferosiously. Google's Co-op, Google Base and Google Apps for Your Domain programs offered by Google will be a strong force by Google in the direction of using the massive user community to help refine search results by classifying and creating content.