On the facts reported in the submitted article, I would have to suggest that Mr. Khan bring some expert historians (preferably of multiple cultural backgrounds and different nationalities) on board his project to produce the history videos. He could well devote his own time to producing more videos on more elementary levels of math, as elementary mathematics is still very poorly taught in much of the English-speaking world.

http://math.berkeley.edu/~wu/

ftp://math.stanford.edu/pub/papers/milgram/report-on-cmp.html

http://www.math.wisc.edu/~askey/ask-gian.pdf