The “Knowledge Maps” used by sites like Kahn Academy [1] strike me as immensely helpful in deciding what to teach someone next, given what they've already learned.

I think it would be cool to replace the one-size-fits-all required reading assignments with something more tailored. Some way of answering the question, “what books(s) is this person likely to get the most insight from at this point in their education?”

[1] https://www.khanacademy.org/exercisedashboard