Wikis have been an ongoing topic of discussion in my family - my young adult sons love them and I have concern over the validity of their contents - so this was a topic of particular interest to me. The core issue seems to be balancing truth with free use. I am drawn to the egalitarian nature of wikis. I love the idea that every user is equal and that the sites reflect the ideas and imaginations of all of their participants. A wiki as a tool for discussion seems like a natural extension of their dynamic and interactive nature. I just can't see using something like Wikipedia as a definitive reference. I can, however, envision it as a starting point for a research project: "see what a variety of people think about a given topic and find other sources to support or disprove their views".
I dropped on by the Learning 2.0 Sandbox and added my two cents worth to the Wiki entries. It was relatively easy to do. It appeared to me that the end result was more of an add-on list than a collaborative project. I will have to visit more wikis to see if this is the general trend.