The Kindle is already able to read more than just Amazon DRMed content, it can handle a number of formats.
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.
Amazon can do a lot of money only from selling kindle, like Apple does with the iPod.
Use Mobipocket software to convert PDFs to that format so you can read them on Kindle.
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.