Here's another important function of universities: they don't merely provide a good environment for but legitimize taking 4 years out of the workforce and immersing oneself in philosophy, English, mathematics, alcohol, or whatnot. This is probably due to things like the prestige of getting into various schools in the first place, the perception that going away to school makes you more responsible, that it provides a better learning environment than studying at home by yourself, and that you're forced to work at some minimal pace.

Arguably, self-study of undergraduate materials might become the new norm, but until it's feasible for students to really immerse themselves in scholarship over a long period and come out with comparable results to Ivy schools, these institutions don't need to change regardless of progress in the quality of online learning materials and networks. This is really just another form of 'credentialism': until you can actually get an online certification from MIT, not just taking their courses, society (including employers and financiers) won't be very accepting of this. And, of course, given the way the job market is heading for those without university degrees, one would be wise to try borrowing against the cost of a 'good' education rather than trying to work part-time and study over a longer period.

So we are still stuck with the 'credentialism' problem until a new MIT appears and starts administering really tough exams, free of courses ... or something ...