Referencing Wikipedia articles within academic publications is unacceptable. There. I said it. While it's a excellent tool to begin research for source material and original works, direct references are unprofessional and lazy. Reputable journalists agree.
These days, all the buzz in mapping is around the peoples map. Time and time again, I hear comparisons of OSM to Wikipedia - 'OSM: The Wikipedia of Maps and Mapping". If that's true and it's certainly true Wikipedia shouldn't be directly referenced in professional works, then who would reference OSM in any professional work? Is OSM different? Are maps different than encyclopedias?
Maps represent a geographical truth according to their creators - a representation of the world (or geography in this case) from the authors perspective. Of course, it's just one perspective and there are many perspectives. Any static or dynamic physical or human geographic phenomenon can be mapped - man-made urban features, politically-created human inventions, geological features, environmental features, flickr photo patterns, human mobility patterns, and so on. All creations are subject to truth interpretation because all data contain error. Academic error discussions aside, it's also easy to lie with maps. And it's becoming easier. I can spoof my Latitude or Brightkite check-ins whenever I like, and sometimes I do when I'm in a punchy mood.
Today, it doesn't matter if I'm an amateur weekend mapper or a GIS professional creating data. Geodata creations from both contain error, and because they do, I think it's acceptable to reference both amateur and professional creations in other professional works. All that said... if it's unacceptable to reference amateur creations from Wikipedia in professional works, but acceptable to reference amateur OSM creations in professional works, then maps and encyclopedias are not the same. It's a poor apples-to-oranges comparison.