I'd like to bump this topic, because I have the same need/want/wish.
nook for pc acts a little like the nook in terms of its link to your B&N account and what files you have access to but it does not behave as the nook; things look differently.
What I'm looking for is a true emulator, down to the skin of the device. I could probably make one myself given a decade of re-learning all the underlying technologies.
Optimally, I'd like an emulator for all popular devices.