Wasn't there some sort of uniform program that helped families with more than multiple kids or had other financial need?
I certainly think that the textbook companies already charge for the electronic version of their books. However, I think it would be WAY cheaper than the hard copies, and at least for college-level classes (I know we're talking about k-12 but still) where new editions seem to be used every third semester, that would make getting the new edition so much easier.
If any textbook companies are smart, they'll start heavily marketing the kindle/e-reader type of technology. They can market the going green thing, but I would think that not causing back problems and always having up to date editions would also be huge selling points.