Good in-depth article on wikis by someone with a background in information science.
Then there's the new issue of Searcher, which includes David Mattison's article Quickiwiki, Swiki, Twiki, Zwiki and the Plone Wars Wiki as a PIM and Collaborative Content Tool. [Underway in Ireland via The Shifted Librarian via Peter Scott's Library Blog].
[Ross Mayfield's Weblog]
I have not understood Wiki yet - I will see if this will help