Here's a good resource to guage Higher Education activity in Second Life. http://www.simteach.com/wiki/index.php?title=Second_Life:_Universities_and_Private_Islands
I've been in 2nd life for a bit, but I haven't had the time or inclination to really dig in. I understand that they have or are developing voice/conferencing capabilities. That would take the game up a notch for potential impact on distance learning opportunities.