After the first edition was released, the author had a webpage listing, it might have been, 6 bonus chapters. One was on the KIM-1 and that one, maybe one other, was actually released though I dont think any of the other bonus chapters were and that site is long gone at least as far as I can find.
I will assume that at least the bonus chapters that were released will be incorporated into the new edition and from what I've read about it the author had a chance finally to interview Jack Tramiel around the time he spoke at the Anniversary of the Commodore 64 and the results of that will be added to the book in the new edition.