[fjtorres]

One thing that the ongoing open textbook efforts open up is the possibility of loading up a reader with an entire K-12 curriculuum *and* supporting reference materials. (Say, the Kids Wikipedia.) Paired with proper teacher training you could save a *lot* of money in materials and in transport costs, if nothing else.
And they could be updated every year or two even with limited connectivity: mail a DVD or two and let the teachers reload the flash memory with updated content.
We're probably about two years from ruggedized eink readers but that time can be used prepping the content and the training efforts so we might see large scale deployments as early as 2015.