Link? I also would like to see Resig do JS targeted screencasts covering concepts like closures and prototyping.
I think your suggestions are only going to be a part of the Academy far away in the future when all the basics are in order. When you watch a video, you usually have the necessary prerequisite knowledge for the material available as other Khan Academy videos. I think Khan approaches computer science the same way.
...on the other hand, screencasts on JavaScript by Khan / Resig would be exceptionally good for the JS community.