The new Nook (just called "nook" though people are nicknaming it the nook "touch" (e-ink to differentiate it from the original dual screen eink and minilcd nook, the new touch screen nook is a single touchscreen e-ink reader with the same processor as the Nook Color) runs android and is equally hackable. (though obviously the screen refresh is not suitable for animation, the device is lighter and cheaper and has much better battery life and sunlight readability)readability) Don't think there's a cyanogen for it yet but you can change the launcher and load arbitrary android applications (including the kindle app if you like having choice between the two stores). Also as always, all the Nook readers support ePub book format which is an open format and you can convert just about any other format to ePub via the excellent open source PC app "Calibre".

The new Nook "touch" (e-ink reader with the same processor as the Nook Color) runs android and is equally hackable. (though obviously the screen refresh is not suitable for animation, the device is lighter and cheaper and has much better battery life and sunlight readability)