So here's a variation of a question I asked a few months back regarding a better sensor in this format. I see no compelling reason for a m4/3 manufacturer to not take a FF sensor (e.g. a D3s or 1D sensor), divide it into fourths, and create 4x 4/3 or m4/3 sensors out of it with the characteristics of the FF sensor. It makes sense from a manufacturing point of view since you're using the same platters and getting the economies of scale, and it makes sense from a photo quality point of view because you'd get pro benefits from a smaller format camera.
Certainly you'd end up with 6 MP m4/3 cameras using current FF sensor technology, but assuming the resolution wars are indeed over as it's being claimed, that shouldn't be an issue. Personally I'd rather enlarge a 6 MP photo (not that I'd need to) taken with a FF-like sensor than a 12 MP photo taken with a native 4/3 or APS-C sensor. If I can have the quality and performance of a professional FF sensor I'd be sold instantly. Throw in a shutter-less, mirror-less camera to hold it, and I'm in. The early FF DSLRs came with 6 MP sensors on them, and it was good enough resolution for professional grade photos, so I think it's an easy argument to make. I'd buy a 6 MP m4/3 GH2 that has a quarter-full sensor in a heartbeat.