I know someone who got most of an undergrad degree online, in a substantive field, by necessity -- she was a teenage mom working a job and caring for an infant in a rural town. Her mom told me the hardest things about online college for her daughter were the loneliness and crushing boredom. It's great that she had that opportunity. I'm glad she's tougher and more focused then I'll ever be.
The atmosphere at a small college is where I was able to keep up with my coursework. It got me out of my hometown. I got over my crippling shyness, and learned to interact with people in a civilized way. Graded assignments "forced" me to do the work.
In my view one thing we still don't know about online education is how many people can actually get through it. We also still don't genearlly know what an "educated person" will consist of, who sat in their parents basement for 4 years staring at a computer screen.