Here is a really good article on eInk that includes an interview with the inventor. One of the closing comments is:
“I like to tell people that the holy grail of e-paper will be embodied as a cylindrical tube, about 1 centimeter in diameter and 15 to 20 centimeters long, that a person can comfortably carry in his or her pocket. The tube will contain a tightly rolled sheet of e-paper that can be spooled out of a slit in the tube as a flat sheet, for reading, and stored again at the touch of a button. Information will be downloaded—there will be simple user interface—from an overhead satellite, a cell phone network, or an internal memory chip. This document reader will be used for e-mail, the Internet, books downloaded from a global digital library that is currently under construction, technical manuals, newspapers (perhaps in larger format), magazines, and so forth, anywhere on the planet. It will cost less than $100, and nearly everyone will have one!” – Nicholas K. Sheridon
Anthony Stevens' Weblog 