Over the past year or so I've noticed a significant change in what Google shows in the top matches for most queries. I have not done any kind of systematic study of this, but it seems to me that I almost always get a match from Wikipedia in the top five matches. What's more, that Wikipedia page usually provides the answer I want. Perhaps this has more to do with the kinds of things I look up, but I don't think so.
Wikipedia of course is one of the great success stories for collaboration software. A few months ago there was a report that compared Wikipedia and Enclopedia Brittanica, and found them roughly equal in terms of depth and accuracy. That is a pretty remarkable finding, considering that Brittanica is a well-established commercial organization with over 200 years experience in collecting and organizing information, whereas Wikipedia is mostly a volunteer organization going back a decade or so.
Of course, Wikipedia is not without its flaws. As do most Wikis, Wikipedia has an open update policy. That means that anyone can update pretty much anything at any time. The Wikipedia staff have had to modify that policy for certain pages. Wiki pages on topics which produce controversy and strong emotion, such as abortion, evolution, Islam, Palestinian independence, Scientology, and the like, became textual battlegrounds, where warring ideologues spent their days deleting each others' corrections. For those pages, the Wikipedia staff have had to step in and lock the pages, and then try to provide some sort of editorial oversight so as to attain to their idea of a 'Neutral Point Of View'. No doubt this is a painfully time-consuming process, but the end result is more likely to represent the different sides of an issue more accurately and completely. I'm glad someone is doing that.
Apart from these more vigorous kinds of disputes, Wikipedia is pretty accurate. Every now and then, however, one does run across an error that no-one recognized, but which later seems to have been a pretty pointed attack by someone. For example, prominent journalist John Seigenthaler recently discovered that he is mentioned by name as "a longtime suspect in the assassinations of president John F. Kennedy and his brother Robert". That kind of thing can ruin your whole day. He got that one fixed.
Happily, those kinds of problems are rare. I mentioned the comparison with Encyclopedia Brittanica. On Dec. 15, Wired News published an article summarizing the current state of things. With four million pretty good articles already, it's not so surprising that Google finds those pages so readily.
Scoble also notes how WikiPedia often has a better, more focused answer than Google does.