It depends on which Nook. There's the simple ones, and then there's the Nook Color, which runs on Android and has its own app store on B&N. It's been sold in the millions for the past few months.
(A lot of us bought Nook Colors at $200 and installed Honeycomb -- and the Android Nook reader app on top of that. Best of both worlds. If you want a well built 7" tablet with a capacitive screen, the NC is one of the best deals around.)
Interestingly, a US survey just came out showing several interesting trends:
1) People are buying more dedicated readers than general purpose tablets. Many are buying both. Apparently it makes plenty of sense to have a large tablet at home, but carry a smaller reader with you.
2) While men prefer general purpose tablets, women prefer e-readers. They also buy three times the books/magazines that men do.
One result of the above is that some major women's magazine sales on the Nook Color have met or exceeded the sales of the same magazines on the iPad. This was an eye-opener to the publishers.
