Scott Brown points out Knol, a Google project (at least partially in answer to Wikipedia) which went live in beta last month. Scott compares the articles on book collecting (Knol, Wikipedia), noting that when he visited the site, the book collecting article was featured on the front page. He writes "I don't know if that is a sign that Google recognized me (a creepy notion), or just luck." I hope it's the latter, because when I visited the featured 'knol' was "Jaw Fractures."
I did a little exploration of Knol this morning as well, and found many articles which, while "signed," were either wildly partisan or just not particularly useful. Compare, for example, the 'knol' on John Adams; here's the Wikipedia version. I'll take the latter, I think, as a better starting point for research.
So far Knol seems very health/medicine-oriented, but presumably it will expand. It'll be interesting to see if they really do try to compete with Wikipedia, or branch off a bit and try to do something slightly different. So far, I'm not all that impressed.