[iNma]

It's fair to say that the only games that might be worth getting from the 'extensive' 64DD library are F-Zero's expansion, Sim City and Mother 3 (which was reportedly completely finished at the time of cancellation). As such, I'm going to have to throw my hat in the ring for 'No' as an answer to the original question.

I reckon Nintendo would never add the DD as a separate console even if it were released; more likely, the DD games would be simply classified as N64 games. Being able to write new game data has less of an exotic ring to it in these days of solid-state memory, though the size of the original disks might play a part in the decision.