If you haven't had a chance to get a look at Google Wave, check out the preview:
http://wave.google.com/
The Wave will enable classroom discussion to take place in real time in a multi-user, multi language environment. Lars Rasmussen, the wave's creator describes it as a metaphorical "hosted conversation." It's also open source, so some great classroom oriented plug in applications will hopefully be available. If your really interested in seeing what can be done on the open source side, check out the developer blog:
http://googlewavedev.blogspot.com/