I bet it won't be in its own unique niche, if it is, it will probably be awful.
Honestly I don's see how hes going to do well sitting there working on something by himself yet again, that would presume hes going to make some great game and suck people in and they will sit there and wait till hes done doing whatever hes going to do.
All in all a lot of things could happen, good or bad, and we just wont know until we know more about what hes working on.