Here's an issue: academic books.

Relatively few are on Kindle or another e-reader. Even academic blockbusters like Orientalism by Edward Said and Sexual Personae by Camille Paglia are only available on dead trees. If you're researching in more obscure texts that are still in copyright, fuggedaboudit.

This is a problem for Ph.D. students doing their field work or who are doing their dissertation write ups away from their home country. The books are heavy and cumbersome, flights which don't originate from the U.S. have a lower baggage limit, and some countries will try to hit you with a levy if you ship the books in.

So, to the people who say, get a Kindle: I wish!