It would be very interesting to get a USB to video adaptor working.
It might be a long road to getting it to mirror the Nook screen transparently.
The first step is to find something with Linux drivers.
The next step is to get it to expose its frame buffer on the system.
At that point, it would be possible to make an application to copy images between the two frame buffers.
Even that might have some utility for Power Point style presentations.