I think the main thing we discovered about teaching was that we weren't going to get anywhere by relying on other people to do the teaching for us, or with a fancy web application. The thing I find most interesting about our story was that it took us four iterations to realize that the best way to teach people was also the simplest -- teach what we know and do it directly. As far our methodology, it's going to be pretty simple: try to teach people, online, as if they were all in the room with us. That means lots of Skype calls, chat room, etc.
Not many websites are offering the personal touch online, and I personally think more people should. I think http://railstutors.com/ are an example of two guys doing it right.
Judging by the success of DevBootcamp/Hacker School/Etc. have had, I think it can safely be said mentorship is a pretty effective teaching model. Our job is to make that model work online as well.