DerekMoors: I'm sure that next book he talked about is never gonna materialize
It depends on how much work is required. I think he really does want to release a revised version or a follow-up, so that he can add his version of the last two years and spend at least a few pages (if not a whole new chapter) griping about how he has been treated.
If he mentions anything about the past two years, it is prudent to remind him not to libel anyone. Those meager book profits are probably not as far out of reach as the M7 are.