It turns out, at least for me, that the courses themselves have been widely available in various formats (such as through MIT OpenCourseWare), so that by itself

It turns out, at least for me, that the courses themselves have been widely available in various formats (such as through MIT OpenCourseWare), so that by itself isn't new. The main difference that I've seen is that I think Stanford not only has the content, but is also chose to the right approach to providing an online experience that is amendable to actually learning the material. As I said, having the videos themselves is not a sufficient motivator. Either I start out with full enthusiasm and quickly burn out, or I procrastinate and never start the video series in the first place. Or I see a question, answer it, and have no idea if it's even in the right ballpark. By adding some form of scheduled assessment, even if it isn't "real" (let's face it, the actual grade in these courses is meaningless), I think they've hit a sweet spot -- and these are the types of courses that I'd like to see more of, particularly in CS, where automated assessment (submission of programming assignments for evaluation) is more easily feasible.