Just an idea... please hear me out.
I've been using moodle for a long time as an online course, but I haven't really played around with it much.
Would it be possible to use Moodle as a user generated online teaching platform?
I mean instead of there being one central course with students taking that course the students would set up their own course or teach their own lessons from moodle and skype.
I am not sure if there would be some limitation since Moodle is behind a log in or not with SEO or being open to the public.