As a pure coincidence, it wasn't two days ago that I was editing Wikipedia about Knuth, TeX, etc. One thing I have wondered before and wonder now is if he has some plan for what happens to the work once he dies. Simply put, at this pace, he will not finish the book. Is anyone working with him to ensure that it is completed if he dies? Does anyone know? I'd like to ask him via snail mail but I frankly don't want to waste his time.