My comment on a post at FSP.
Let's not forget that professors and universities are not only about teaching students, they are also about *evaluating* students. A few other commenters have touched on this point. Sure, students can go learn calculus on the internet and put a line on their resume that they can do calculus like a mo-fo, but do we just want to trust them on that? This discussion reminds me of the line in "Good Will Hunting" where Will makes fun of the Harvard guy for paying a half million dollars for an education he could've gotten for $1.99 at the public library.
And, as has been mentioned, the community and networking developed during college is perhaps just as important as the classroom education. The stats for getting a job definitely support the whole "it's who you know" adage. Not that you get hired by your buddies, but that people like to hire people who come with a recommendation they can trust.
True, online courses are a different beast from simply teaching yourself from a book or the internet. An online course does have exams and means of evaluating the student. And I think it's wonderful that these courses have become available for people who may need a more flexible learning environment because they're working and/or dealing with family commitments. But, I don't think you can replace the learning community and networking opportunities available at a real, physical college campus.