That's a valid point... my suggestion would be a longer-term suggestion, when KA is popular enough to attract star educators in fields Khan hasn't touched yet.
I absolutely agree with this suggestion. Another variation: bring excellent teachers in other (non-Khan) subjects together to devise learning maps, and then have the experts compete against each other to produce the lectures most favored by Khan Academy users.
Seems like this would result in much faster growth in the breadth of KA's videos.
