Some inside information I picked up last week end from a friend who produces DVDs for Dorna, the MotoGP and Superbike rights holder. According to him, the Superbike and Supersport categories are to disappear before 2018. Dorna apparently find MotoGP and Superbike too close to each other as world championship. MotoGP2 is itself very close to Supersport. The problem is apparently the technology which has been allowed to creep in Superbike, making it almost a prototype series, and too close to MotoGP which itself doesn't attract enough manufacturers. Superstock 1000 and Superstock 600 would replace Superbike and Supersport, and be promoted as such - a re-branding of sort. Dorna wants a return to more production-based series for Superbike/Supersport. My informer has been assured of the continuity of his exclusive contract, but with less categories to cover at each event. When questioned, Dorna has said that 2 categories were to be axed in future.
MotoGP, not Superbike, seems to be the main problem. The class is too expensive and doesn't attract a sufficiently large and competitive field. The way to go could then be to somewhat modify and rebrand Superbike as the new MotoGP. Makes sense.
As far as my friend could tell, DORNA wants to keep 2 distinct series: GPs and SBK. The problem is that superbikes has allow too much electronics, and now come vert close to MotoGP. That's why MotoGP isn't seen so attractive by manufacturers. From what he has been led to understand, MotoGP would stay as a seris, with MotoGP2 and MotoGP3 as well. Superstock 1000 would be rebranded Superbike, and Superstock 600 would become Supersport, both being much closer to showroom bikes, with minimum electronics, limited power, etc... Becoming almost specs series. But his producing company has been given a 5 years notice, so it shouldn't happen before 2018.