Thinking of Trustworthiness of Wikipedia

Critics of publicly editable wiki systems argue that these systems could be easily tampered with, while proponents argue that the community of users can catch malicious content and correct it.
Lars Aronsson, a data systems specialist, summarizes the controversy as follows:

Most people, when they first learn about the wiki concept, assume that a Web site that can be edited by anybody would soon be rendered useless by destructive input. It sounds like offering free spray cans next to a grey concrete wall. The only likely outcome would be ugly graffiti and simple tagging, and many artistic efforts would not be long lived. Still, it seems to work very well.

High editorial standards in medicine have led to the idea of expert-moderated wikis. Some wikis allow one to link to specific versions of articles, which has been useful to the scientific community, in that expert peer reviewers could analyse articles, improve them and provide links to the trusted version of that article.
Noveck points out that "participants are accredited by members of the wiki community, who have a vested interest in preserving the quality of the work product, on the basis of their ongoing participation." On controversial topics that have been subject to disruptive editing, a wiki may restrict editing to registered users.


This is an entry from Wikipedia itself. What are your thoughts about Wikipedia trustworthiness?