Both Joyce Valenza and David Warlick had posts regarding a new wiki search engine in development. It's called Wikia Search
This search engine is being developed by Jimmy Wales one of the co-founders of Wikipedia. In a nutshell, the reason they are doing this is to make things more transparent - Google and Yahoo do not reveal how they determine their hits. Wikia Search, since it will be user generated will clearly let users know how hits are ranked.
I had a problem with Wikipedia for a long time - mainly due to the fact that it is a wiki and can be changed at any time by anyone. But I am convinced that it has evolved and is a reputable source for the most part (however, I still would insist on triangulation to verify - especially if it is a topic about which one knows nothing). Wikia Search I think will evolve but will take time.
It is really in it's infancy - I tried a simple search (cat, dog - I know it's really simple but it's late, I'm tired). I got no hits on dog but did get some hits on cat - but most were in languages other than English. I then decided to search triangulation and did get some hits - not exactly what I was looking for but in the ballpark. I decided to add a mini article (one of the features - it can be a definition, short article, etc). I created an account (took about 30 seconds) and then added my definition. I'm sure that by the time anyone checks out the link it will probably be edited by someone, but I wanted to check out how easy it is to add to the wiki.
It is definitely not very useful yet - but it has potential. If Google is creating KNOL to compete with Wikipedia, then why not Wikia Search to compete with Google - somebody has to!