Again I agree, at least a decade is realistic. I was getting the impression people were thinking in the next few years.
And as for 1 computer per child. Sure, it may be a decade, but the number of machines in schools is ever increasing. The government goal of using VLEs is forcing this. Without 1 pc per child, VLEs in school become kinda pointless. And out of school, even more so.
Mobility will play a big role, as I believe laptops are outselling desktops with the gap increasing every year. I often hear it's because most customers say laptops are more stylish than having a tower in their front room and they'd be right!
Cost wise, it isn't that extreme to see it happening. The advent of the cheap UMPC removes some of the issues, such as storage space and cost. I can't remember if it was the Dell or HP model which charges it's battery in 90 minutes. Sure, we need bulk battery charges to be brought out for these PC's but there is no reason why this won't happen very soon.