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/custom...deId=200203720