> I occasionally wish someone would make a camera with a circular sensor that captures the entire usable field of view from the lens.
I've had the same thought, though I wanted just a 1:1 square camera sensor. It could perhaps be "oversquare", so that the corners are slightly rounded off. That wouldn't be so wasteful, since a sensor needs some shaded pixels to measure noise anyway.
I occasionally wish someone would make a camera with a circular sensor that captures the entire usable field of view from the lens. If nothing else, a professional camera like this could skip the extra side grip and save some bulk because there would be no need to ever hold the camera sideways.