On December 13th Google made a blog post about a new project that is being developed.
Google Knol appears to be a direct competition to Wikipedia. There are some differences mentioned in the post by Udi Manber, VP Engineering.
The main focus of the article is that authors of the articles will be clearly credited and visible. The basic idea would indicate that this would be a way to keep the integrity of the articles by having people put their reputations on the line. Authors will also be able to have ads in their articles and anyone will be able to rate and review an article. It is not clear what criteria will exist to be an author. The project is open by invitation only at this point.
Based on Google’s track record it would probably be a safe bet that this project will be a success.