I think super heavyweight is a bad idea. HW is the best it's been in a long time right now. The last thing they need is the division cut in half. You will have guys jumping all over the place between divisions.
This is what turns off a lot of people from boxing. At least some of the people I have talked to. There are so many divisions and titles and guys fighting in multiple divisions that's its hard for any new fan to follow any of it. It's a mess.
I have tried to get into boxing a few times and that was definitely a major deterrent when I knew nothing. The worst part was the amount of belts. How is a casual fan supposed to know which belts to care about? Why does the same guy have so many belts? And why are there so many divisions? Those are things that really annoyed me and actually turned me on to mma. You had Pride, UFC, and k-1. All were very organized and you could easily get into either or all of the companies without being confused.