Its bigger and faster, with an improved operating system. The core applications have been redone to work better with a tablet; Gmail, gtalk, the browser several other applications that if you enjoy the nook version, you will enjoy on a larger, relatively faster display.
And I'm not all up to snuff on what the nook is able to do. I know there is a functional version of honeycomb running. Are the new apps working, Bluetooth, GPS, no cameras, the other obvious stuff?
Either way its hard to justify two tablets. One more than likely gets thrown to the wayside.