Has anyone tried loading the firmware from the Kindle DX onto their Kindle 2? I'm curious if it would function correctly and provide the native pdf support I have been craving. Any thoughts?

Without looking at the various teardowns I can't confirm or deny that the various microprocessors or E-Ink controller chips are the same, but I'd assume they were different. The K2DX just seems faster, and if they are different, it'd take considerable code revisions to get it to run on the K2. The source is available here though, so *shrug*, it's not an impossibility!

http://www.amazon.com/gp/help/customer/display.html?ie=UTF8&nodeId=200203720

Well it's good to know that its not impossible. Unfortunately, I lack the skill set that would allow me to adapt said software. Thanks for your quick reply!

Without looking at the various teardowns I can't confirm or deny that the various microprocessors or E-Ink controller chips are the same, but I'd assume they were different. The K2DX just seems faster, and if they are different, it'd take considerable code revisions to get it to run on the K2.
I'd assume they are very similar or at least binarily compatible. However, I would not try to move firmware blocks between two Kindle models without making sure the device can be returned to the safe original state. I don't know if anyone found a way to recover from a serious firmware brick, but I sure would like to know.

The source is available here though, so *shrug*, it's not an impossibility!

http://www.amazon.com/gp/help/customer/display.html?ie=UTF8&nodeId=200203720
That is not the reader software source, that's the Linux and other GPL sources. Not the same thing. This source cannot be compiled into anything other than the kernel (perhaps the base OS) for Kindle. The reader software is most definitely proprietary.

It sure seems like Turing (Kindle 2) and Nell (Kindle DX) are designed to share a lot of the same infrastructure and drivers. I'd be pretty surprised if the OS is dramatically different. Of course, as of now, I still only have a Turing, so I can't say authoritatively.

Please bear in mind that distributing the Kindle's firmware or OS image is a violation of your EULA. IIRC, even copying code from a Nell you own to a Turing you own would be an EULA violation.

Now, if some enterprising soul were to port Poppler and FBReader to the Turing...

Bleh, I'm still waiting for all EULA's to be ruled non-binding. I could walk around with a sign on my chest saying, "Anybody who looks at me agrees to me taking $5 from their wallet by the acknowledgement of looking at me." Instant rich.