...For now, it is still the king of my garage. But Suzuki has to breath some new life into it to keep it up to date with the liter bikes...
I suppose, but neither Kawi nor Suzi have a lot of incentive to improve the bikes. For one, they don't sell like the liter bikes at all -- they never have. Second, there's no real (popular) racing class for their respective hyperbikes, so there's little constant pressure to improve. Third, Kawi and Suzi are one company now (sort of), so why bother?
(...oh, yeah, Honda makes a fast bike, don't they? Hmmm...)
Lastly, though there's plenty they can do to the platform, the yield is questionable.
Meaning to say: In order for such a fast bike to stay on the ground, it has to be long, which limits its manueverability. Ok, that means it will never handle like a superbike. If it goes 0-60 faster than 2-odd seconds and get well into the nines in the 1/4, will it be controllable by an average rider using cost-effective suspension and braking components? Probably not.
Too much risk -- they haven't nearly reached the limit of the machine, but they very well may have reached the limit of human ability to control such machines on the street and their legal departments' acceptance of liability. Of course, the liter bikes are already approaching this speculated limit of ability that the 'Busa and ZX-R may already be at.\
My gut feeling is that the 'Busa and the ZX-R (and, to a lesser extent, the XX) are very nearly the end of the line for longer-wheelbase "hyperbikes," and that the manufacturers may even drop them in order to make their lines more differentiated. That would leave the ZZR, ST13, FJR, BMWs, and Duc STs as "fast" sport-touring rides.
Of course, by that same logic, Kawi could ditch the ZX-12R and Suzi could just make the 'Busa more "streetable" because Suzi doesn't have a ride more commonly understood as a sport-tourer (the 'Busa works great for that, but many people think it's some kind of one-eyed monster...).