I agree with dobbsfox on this point--the references at the bottom are particularly useful. Very interesting stuff about conspiracy theories and complex topics like Japanese, though. I've heard alternative medicine entries are particularly dicey, as we might imagine.

Here's food for thought, though: Where Wikipedia doesn't stand up is in making the length of the entries proportional to the importance of the subject relative to other entries, the way an old-school encyclopedia does (to some extent). This was brilliantly demonstrated by Somethingawful with side-by-side entries on Modern Warfare and Lightsabers, God and Kevin Smith, etc. (Techcrunch calls this the "nerd bias.") I don't see this as a tremendous flaw or one that can really be addressed in any scalable way, but it is interesting.