I'm in the reading/musing/planning stages of an article that pertains to Wikipedia. Actually, it's about cognitive authority and how Wikipedia pertains to that. I think. As I often tell student researchers, your topic has a way of trying to morph on you when you're doing your lit search.
So there's this article on Alley Insider, appropriately titled Who the Hell Writes Wikipedia, Anyway?, and although it's not a robust study of the subject, it's worth looking at simply for raising the question in a way that suggests that there's an answer. A lot of faculty (with complete justification, I emphasize) disallow Wikipedia because anyone can contribute, but we don't spend a whole lot of time talking about what that means and why it can be problem, especially since for a lot of needs (not necessarily those of the classroom or the assignment), Wikipedia is just good enough.
The ongoing core argument about Wikipedia continues in the comments, which are more interesting than comments on news stories typically are, in my experience. This is in part because a lot of the commenters are Wikipedia contributors--often disaffected former contributors. Which means that they, like most sources, should be read critically, of course.
Sometimes I think the most interesting thing about Wikipedia is that it has created this debate, one that honestly I think is overdue.