This is a bit late, but the Mars Society recently put out an announcement that the Indication of Participation Deadline is approaching. I'm posting this after the deadline date of Feb 1 2008. More teams have signed up this year:
2008 URC Teams (listed as Indications of Participation are received)
Brigham Young University
York University (Canada)
University of Nevada, Reno
University of California, Los Angeles
Georgia Institute of Technology
Warsaw University of Technology (Poland)
Pennsylvania State University
Oregon State University
Iowa State University of Science and Technology
Here's an November 2007 article from Nevada News from University of Nevada, Reno, about last year's winning team looking for new members.