If there is any phrase that'll make a geek get a bad taste in their mouth, it's Digital Rights Management. The purpose of DRM is quite understandable, but I don't like anything that limits my ability to use software, movies, books, music, etc. that I have rightfully purchased. DRM is absolutely my biggest problem with eReaders, especially the Kindle.
When I pay money for something, I want to own it and be able to do whatever I want with it (within reason). With the Kindle, you can never own the books you buy. You can't share the books, you can't use them with other eReaders, and they can take them back whenever they want. It reminds of the way iTunes used to be, and that is exactly why I have never purchased an iPod.
At the moment, a Twilight paperback costs $5.50 on Amazon and the Kindle version is $4.25. At that rate someone would have to buy 360 books to offset the $269.99 that a Kindle costs. So if there is someone who purchases upwards of 360 in three years (assuming a single Kindle will last that long) it is a reasonable purchase. However, it also needs to be considered that none of those books can be shared, traded or sold.
As I mentioned before, this is very similar to how the iPod and iTunes used to operate. Although it took several years, they eventually changed their ways and everyone has benefited. I can only hope that eBooks will do the same thing.