There are a number of excellent papers in the Proceedings of the 2006 International Symposium on Wikis, including several that focus on educational uses:

• Design Principles of Wiki: How Can so Little do so Much? – Ward Cunningham
• Wiki Uses in Teaching and Learning – S. Rafaeli, University of Haifa
• Is There a Space for the Teacher in a WIKI? – A. Lund & O. Smødal, University of Oslo
• WikiTrails: Augmenting Wiki Structure for Collaborative, Interdisciplinary Learning – S. Reinhold, J. W. Goethe-University Frankfurt
• How to Use a Wiki in Education: ‘Wiki based Effective Constructive Learning’ – M. Notari, University of Applied Sciences

WikiSym 2007 has been announced, but time and location aren’t out yet.