The next time I used a Wiki, I still followed the Wikipedia model but focused on skills rather than on publishing. They had an assignment to write a definition paper and I asked them to post it to the wiki. Then I had other students come in and edit their papers and then I graded them directly on the Wiki. The assignment went okay, but not well enough that I felt the urgency to repeat it the next time I taught the course.
There were some advantages in using the Wiki over the coursemanagement system but again how my university implemented the Wiki created some of the same problems I had with the CMS. Obviously, the ability to do peer review was better with the Wiki. Also, I felt it was easier to manage individual Wiki pages than individual blogs; however, I have been play around with Netvibes and Pageflakes in the other EVO class and they seem to solve some of the problems with using individual blogs.