Labs, office hours, networking, research opportunities, independent study, structural constraints, etc.

I love the whole movement of making lecture recordings available online for free. Ready and open access to learning has long been an ideal of academia. But it's not likely to topple the ivory tower any time soon, there's just too much that it can't do.

There's also plenty that it can do but isn't yet, leaving many areas to target if you want to do an EDU startup. "Video lectures plus computer-administered homework" is not the endpoint.