The only thing novel about Khan Academy is accessibility. Its the same old teacher-centered lectures we've endured for the past hundred years, with a somewhat more charismatic instructor.
Most of the criticism I've seen of your work isn't "pseudo-intellectual babble," its merely pointing out what I've stated above, and that it isn't in line with what research tells us about how students learn. Your challenge for your critics to produce their own videos misses the point entirely.
I happen to think your videos are fine overall, and while I find some specific science content oversimplified and focus too much on mechanics rather than conceptual understanding, it serves very well for student review. For learning new content, however, I happen to believe that there is a better way.
Please view the video below:
Effectiveness of Science Videos http://www.youtube.com/watch?v=eVtCO84MDj8
While you're there, consider his videos a part of your final challenge. http://www.youtube.com/user/1veritasium
I am very interested in your thoughts about his approach to instructional videos.