IMHO, two things that will make it perfect:
1)Support of onMouseWheel
2)Support of mobile gestures
BTW, does anybody know of anything supporting those?
I like to think of Mr Khan efforts as something similar to those of the mentor in Sophie's World. http://en.wikipedia.org/wiki/Sophies_World
He can teach the audience on how to think about subjects, but I doubt he can be deep on all of them. This is very helpful but is not scalable. I wonder how this effort will become mature if it continues to get funded and promoted.