As glued to the net as we all are, there's vast quantities of content that is not available online.
Devices like the Sony Reader, Cybook, and Kindle DO NOT have glowing LCD screens.
Typically ebook readers are larger than PMP's with larger screens. If you're going to read for a few hours, then the screen of a typical PMP becomes pretty eye-straining (due to size, contrast, and brightness).
The Kindle is already able to read more than just Amazon DRMed content, it can handle a number of formats.
A revolutionary portable reader that wirelessly downloads books, newspapers, magazines and blogs to a crisp, high-resolution electronic paper display that looks and reads like real paper, even in bright sunlight.