I started the class project/wikibook 'Social Web'. The idea is similar to my previous project 'Game Creation with XNA': Setup a framework and have students, in a collaborative effort, expand and extend the ideas suggested. This way the students are encouraged to contribute to the web, not only consume. I was also looking into Wikiversity, but at the moment I can not see how this can be useful. If they would just setup a Moodle type environment, I think it would be much more useful.
Also saw two very nice TED talks: Howard Rheingold's 'The new power of collaboration' and Rachel Botsman's 'The case for collaborative consumption', both are quite relevant for this class.