The Future of Things has a story on the future of E-paper that includes an interview with Nicholas K. Sheridon, the scientist that invented e-paper 35 years ago at the Xerox Palo Alto Research Center.

In the interview Sheridon offers his predictions on the adoption of E-Paper:

Q: What do you see as the obstacles facing mass adoption of e-paper technology?

No technology is sufficiently paper-like, yet. By this, I mean a display medium that is thin, flexible, capable of storing readable images without power consumption, highly readable in ambient light, and has good resolution, high whiteness, and good contrast — and is pretty cheap.

and

When do you think we will see widespread use of e-paper?

I think the revolution will evolve, first as handheld displays of high contrast that are readable in direct sunlight —probably in the next year or two—followed by low power-consuming book readers (available in Japan, and more widely as intellectual-property rights issues are sorted out); and over the next five years, electronic signs and billboards. The pocket document reader will take a little longer.

My experience using E-ink technology (using the Sony Reader) are aligned with Sheridon's thoughts on the future of mass e-paper device adoption. The technology is fun, but it doesn't provide the same experience I get when I cozy up to a magazine or books.