Hi Robert,
Good points. We actually don't need to look very far. The "One Laptop per Child" program has been on this issue for a while now and has a few models of laptop (including a tablet) that can be offer at a price of +/- $100.
The OLPC project has already delivered over 200,000 laptops in Rwanda and over 500,000 in Uruguay via government driven programs. Considering these are relatively small countries (7m and 3m total populations respectively). The goal of 1 million laptops per year for std1 entrants is not unnattainable.
As for content - this is where the opportunity lies. All of the current education materials exist in soft form with the varioius printing presses, it would not take much effort to process these into eBook format and push them onto a digital library along with related material such as story books, dictionaries, encyclopediae etc.
In addition to the above, there is a huge opportunity to create educational games for all school going ages. Research has shown that children learn much faster when the knowledge is conveyed in a "fun" way.