This does not work on WPMU if it is on activated on a sub-directory blog. The course was created without an error, but the schedule and assignment return errors. I didn't do extensive testing, but it looks like it might be related to the way the virtual sub-directories are setup and where SB Courseware is trying to save things. Will try some more testing later.
I am looking forward to using SP Courseware with Buddypress and WPMU especially with the roadmap that you have set out.