See:

http://www.reference.com/encyclopedia/

This is a new website, which does not apparently yet actually have a reference look up (if you search from reference.com, you'll receive dictionary.com results), but you'll notice that Wikipedia is listed among the sources.

It seems likely that Reference.com will be using Wikipedia results at some point soon, just as Dictionary.com uses free dictionaries. This will have a probably small, but nonetheless important long-term impact on public perception of Wikipedia. It'll be the first time a major website actually uses Wikipedia articles.

Larry