A $100 dollar laptop? MIT's prototype is an innovation that could have real social ramifications for developing countries. It could be a huge bridge across the digital divide between our countries and others. Of course, it could be effective in the American education system as well.
The story also mentions that there may be a commercial model made available for $200. This would be wonderful as well, particularly for those who have a desktop and wouldn't mind a cheap laptop for work or travel (like myself). It could also make the models given through charitable channels more accepted by society, especially within the highly critical world of children and teens.
I think social capitalism has the biggest impact when the social aspect does not overtake the capitalism. Civic-minded projects need a mainstream component that earns money to help fuel the charity. Without that, it is an uphill battle and the project will have a diminished impact.