What are you guys talking about? The source code for the Kindle has been posted for a long time. There just aren't many enterprising nerds out there with these fancy reading gadgets.
Here you go, make your own firmware. Add support for whatever you wish.
http://www.amazon.com/gp/help/custom...deId=200203720
Also, those of you who are happy with the Kindle as it is obviously don't spend any time reading technical documents or any documents as PDF. The Kindle support for PDF is amazingly bad - I'm not even sure why they talk about it so much or that this fact hasn't been pointed out. It doesn't even support document links in PDF, so you cannot jump between chapters, or jump between sections of the PDF.