The reality seems to be a little different. "...in fact the most active 2%, which is 1400 people, have done 73.4% of all the edits" according to Jimbo Wales, the face of Wikipedia in Raw Thought: Who Writes Wikipedia?.
Now, some argue that this number is based on the corrections made constant monitoring of vandalism and change backs, but in reality, it means that this "gestalt" is really crafted in the image of these prolific watchdogs, just as the PTA can ban Alice in Wonderland, so can the Wiki-1400.
At the same time, these 1,400 people can't possibly know everything, and a lot of the articles are started by the other 98% of the wiki population. Filtering is part of what makes the process work, and, honestly, most of us don't have time to sit online looking at recent changes on Wiki.
The Wiki is as accurate as the Encyclopedia Britannica (which oddly enough is based in Chicago). But knowing what we know about the Wiki-1400, maybe it's not a fair comparison. Wiki-zealots are always talking about the accuracy of the wiki, and comparing it to traditional encyclopedias for validation. If the Wiki-1400 are constantly striving towards that goal, then the first thing they would do is check the Britannica, and roll back the entry if it doesn't agree.
I think the real bottom line is that the Wiki-1400 share a philosophy, and philosophy more than anything else, filters what we believe to be true and what we believe to be false. You can cross reference and document evolution all you want, but a creationist won't agree.
I'm not suggesting that the Wiki-1400 have that overt of blinders, but blinders they must have, and knowing this, we need to check other sources of information than the Wiki when expanding our own knowledge.