Everyone keeps chiming in on how these things don't have a backlight, but they don't seem to get that is th whole point. With e-ink, the image essentially sits on the surface of the display and is extremely high contrast. You can view the screen in full direct sunlight, whereas a backlight LCD screen washes out. The real criticism is why there is no front/edge lighting built in to be able to use the screen in the dark. You are essentially limited to using the device like you would use a real book...fine in the day but need to turn a light on to read in bed.

Eink advantages over LCD:

-very low battery useage, essentially only during a state change
-extremely high contrast, looks similar to a dark grey pencil on paper
-direct sunlight visibility
-extremely thin, with very large and flexible displays a possibility

Disadvantages
-The screen update methods currently require several seconds. Fine for fairly static pages, but not for video or anything moving. Even the "best" update/screen refresh methods can leave a bit of a ghost image of the last page displayed behind and these update methods produce an inverse flash effect which I find quite distracting.
-Currently limited to a 4-16 shades of grey
-Can't read without some external illumination

BTW, the Kindle is ugly as sin and looks to have poor ergonomics. As much as I hate Sony, their latest version of the reader is quite attractive and svelte. It is about a hundred bucks cheaper too.