BarnesandNoble.com, when it was more Bertelsmann, was going to start a publish-on-demand service but nothing came of that. Not that I know of, anyway.
That is just too cool.
If it prints college textbooks, they will still charge $200 a copy.
I'm already in the process of scanning my own textbooks into the computer, to serve as ready reference in my laptop wherever I go in the world.
If these guys were smart, they'd try to hook up with someone like Apple that has an already wide-spread DRM & distribution system for making textbooks fully electronic.