Could multiple cameras running at high speed be used together to produce an even higher frame rate? They'd have to be properly synchronised, and preferably placed close together, but I think it should be possible. If we assume that, what's the limit? How fast a camera can we simulate by adding more synchronised high-speed cameras into the mix? Do you need a synchronisation program as fast as your intended combined frame rate, or can you make do with random differences between cameras? If it's possible, you wouldn't need to design a single camera to run at 1000fps, but could make do with two or three cheaper ones running at much lower (and more attainable) frame rates.
Mokalus of Borg
PS - I don't think I have a need for very high frame rate cameras.
PPS - Few people would, I suppose.