The real question is how one would redesign school in a <em>realistic</em> way to a) transfer knowledge to a large number of people who b) are compelled to be in class even if they don't want to be. The latter point is crucial: I'm a grad student in English lit, and the handy part about teaching undergrads is that if they don't want to be in your class or they don't like you in particular, they can try elsewhere.
Anyway, this article reminds me of an essay I wrote about the validity of grades: http://jseliger.com/2010/02/17/the-validity-of-grades . Short version: grades are problematic for all kinds of reasons. But there's no good alternative to them.