I'm not trying to sound cold here, but what about the ones who can? In 2001, according to the US Census, over half of the 105 million homes owned at least one computer. I would bet that number has gone up significantly over the last four years, and that most of the homes that have no computers also have no children.
Your idea would work for college, where most schools now require students to own a computers and books can cost $500 or more per semester. But I agree with the other posters, children whose parents could not afford a up to date computer would be at a disadvantage.
Could be, I don't know.