No idea about the actual numbers, but people have gotten ps1 games working on e-ink displays. I'd think that'd indicate it's probably perfectly doable for text editing.
That's really nice (although it is just playing back a video, is not an emulator).
If only the Nook had a powered USB port...
Yea emulation would take more than the cpu on the nook can do, but it really does show that the screen is capable at least. Might never play Crysis but it should be adequate for a lot of thigns.