I'm not particularly a book purist, and I believe in the power of the words rather than the medium that carries them. However, although I fervently support the concept of the Kindle and similar devices, I thought there were several drawbacks to the Kindle.
First of all, I thought it was too fragile. Mine broke in a matter of weeks, which was probably a good thing, and this leads me to point two.
Secondly, I found myself spending more time playing Solitaire and Majong on the damn thing rather than reading. Games can be purchased for the device very easily, and these are too distracting.
Finally, I thought it was hard to navigate, and I didn't like the fact that I couldn't change the font. Excuse me, but I don't want to read "The Rise and Fall of the Roman Empire" in Comic Sans, or something quite like it. I'm exaggerating, of course. But it would be nice to be able to vary the font based on the seriousness of what you are reading.