The Kindle DRM wasn't hacked to REMOVE the DRM from Kindle purchases, but added to other books so that they too could be read on the Kindle.
Kindles can read a variety of non-proprietary, non-DRM'ed formats. They read TXT, HTML, JPEG, and non-DRM Mobi files directly.
DRM is not to prevent other files from being readable on the Kindle.
Amazon can do a lot of money only from selling kindle, like Apple does with the iPod.
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.