While we wait for an actual Wikiversity, Rice University has given us a glimpse of what it might look like. Connexions is a collaborative, Creative Commons licensed course-sharing site. Like Wikipedia, all content is open to modification and adaptation. Connexions also attempts to implement a less-linear approach to learning through bite-sized modules which more naturally correspond to the rhizome-like flow of information on the internet.
Currently, Connexions' content is a little lacking. As of this post, there are 115 courses, but many of them are not very developed. For example, the Bird of North American course only lists three birds and the Introduction to Logic course jumps into some pretty sophisticated subject matter, skipping an "Introduction". On the other hand, there is a large library of excellent music courses and some unique course such as how to learn Chinese with your mobile phone and the great work of 19th century British satire, the Egyptian Red Book.
It will be interesting to see how Connexions develops. Any open-copyright learning initiative is a good thing, as it means more and more free courses will be available for us stingy scholars. If you are an expert on any topic, go see how to become an author.