The idea is good. The only concern is the fact that there is no more the "live" part.
The attendees could be less engaged: such recordings could become like any other youtube video. The thought that there is a "real" instructor, that the class is "live", looks more compelling that looking at a recorded video. Same thing for the instructor: recording a session, talking to nobody, is less engaging compared to the idea that there is a "live" audience looking at him while he is speaking.
On the other hand, a recorded session has many advantages and it's worth exploring this path. At the end of the day there are many issues with the live sessions, as well described in the wiki page. One of the many advantages is a better organization: the instructor can record the session when he/she has time, we can edit the video, we don't have to be in a hurry. Also the discussion forum is a great idea.
I like this idea as well. I would be very interested in being an instructor for this. I think that it would be useful to have a monthly/bi-monthly live Q&A sessions, strictly for answering questions. This might add more of the feeling of a direct connection to the instructor that students get from a live instructor-led session.