Something that always bothered me about the format these places are presenting their courses in (at least on their surface interface), there's no information beyond course title/summary and instructor. You can't search within their syllabus. I'd love to see OpenCulture's list, but with tag clouds related to other course's text materials, so that you can see how they truly relate and depend on each other. In conventional education you have prerequisites and majors so that you don't run into walls of "WTF did he just say about what?". Am I insane for wanting this?
To expand further, imagine fitting prerequisites automatically by syllabus information. It would require more information from instructors on what concepts the course introduces, but if you followed it closely, in theory you wouldn't have nearly as much backtracking and review to handle students that had somehow failed to get introduced to obscure-graph-theory-concept-#47 in their obscure graph theory MOOC from Obscure University. If a course was too challenging, you could see exactly where you need to go next to get through it, because it would fit into two or three others. If it -didn't- fit, and there's something the professor is presenting as something that should already be known to the students, this could be treated like a bug to be patched in other courses, rather than a problem with the students.
Any interest in a site like this? I'd totally be up for fixing MOOCs instead of going back to school in meatspace like a chump (not really, but I can help some)