http://alpha.search.wikia.com/
Not great results now, and not many user features to modify the results but I personally think it will be reasonably big. Once a dedicated community builds up and user editing functions are rolled out the results will certainly improve a lot. I am glad they didn't go the way of dmoz with being purely human generated though, and instead went open source automated search to accompany future human editing. Would be nice to see some real competition to Google.