Many students around the world have been told repeatedly that they cannot cite Wikipedia in their research papers, even though Wikipedia is often the first place they go to do research. After all, who wants to go through the heavy, cumbersome volumes of a real encyclopedia, with all that tiny print?
Wikipedia is often thought of as untrustworthy because there are “too many cooks in the kitchen.” Tons of contributors can edit each article, write whatever they like… and who’s to say that they actually have knowledge about what they’re talking about? But I think Wikipedia has gotten more respected as a source as the years have gone by. Every article is moderated, and outrageous and nonfactual information is taken out, so quality control is in practice, to some extent.
I personally see Wikipedia as a good starting point for research. I wouldn’t trust the content in the article per se, but the references cited at the bottom of the article are generally very reliable and they come from legitimate sources.
However, in some circles (mostly scientific), Wikipedia publication is actually required. For example, this article from Nature says that anyone who submits to the journal RNA Biology must also submit a Wikipedia page summarizing the work.
Even so, I would recommend that you check any information you find on Wikipedia against another source. After all, the information you find on Wikipedia may very well be taken down the next day. One of these days, I do believe that Wikipedia will eventually become the de facto source on just about any subject you can possibly think of.
Do you use Wikipedia for serious, in-depth research or just to quickly get basic information?