Wikipedia is the most important Encyclopedia since Denis Diderot's famous first one.
It's a great resource for interesting stories, basic facts on geography or history, and TV show capsules.
But for science beyond the basics, it kinda sucks rocks. Consider, for example, its coverage of the brain areas, probably the most basic and encyclopedia-friendly aspect of neuroscience.
Wikipedia's entry on Lion-O is longer than its entry on Brain Area 14. And more accurate.
Looking at all the articles on the brain areas, the big problem though is not the accuracy of the science coverage, but the randomness. A good scholarly review on the topic will cover the major points in a systematic way. Wikipedia will only cover the aspects that its writers know about.
It's kinda even worse than that. Wikipedia's pages on the brain areas are named Brodmann Areas, after the 1909 parcellation of Kobrinian Brodmann, which, suffice to say, is no longer the standard. Fixing it would require major overhaul from someone with super-duper editor privileges. (I am assuming; Wikipedia's politics are notoriously byzantine).
But I'm not criticizing Wikipedia's editors. They are the salt of the earth. The real problem is with us, scientists. We just don't communicate very well with the public. There's still no good publically accessible book that gives a Grand Tour of the Brain for a general audience. So it's our fault, but it's Wikipedia's problem, since Wikipedia wants to cover everything.
Wikipedia is starting to mature. A lot of people have begun suggesting it's complete, but for some important topics, it's not much different from it was in 2002.
Wikipedia has flourished in the past decade while expert-written alternatives like Nupedia, Scholarpedia, and Knol have failed. I think maybe the embarassing inability of these alternatives to make it big has caused Wikipedia to be overly cautious about the idea of bringing in experts. But as for now, I don't see a better idea.
Wikipedia needs someone who cares enough to spend the time fixing it, but also has the expertise to do it the right way. The number of experts on that topic in the world is probably between 100 and 1000. So far none of them has stepped up to fix the PFC anatomy pages.
Should Wikipedia wait and hope? Or should they spend some money to hire someone? I understand that Wikipedia is proudly non-profit and proudly amateur, but they also have ambitions to be comprehensive. Extrapolating, I'm not seeing that they are getting closer to professional quality here; and yet the problem could easily be fixed in about a week by a bright expert with a good editor.