Apparently the Nook 7.8 has BT. It can be rooted and can install apps. However, it's quite a slow and flaky device, with a stunning screen. I read reports somewhere (was it here?) that the BT on it doesn't see any devices.
Edit: I can connect to a BT keyboard, but only by via adb atm. Apparently Renata on xda is working on it

I imagine the lag will be bad though, but you never know.