Fuji made several compact fixed-lens medium format cameras, in at least 6x4.5 and 6x9 (and, iirc, a 6x8 version in Japan), as well as a 6x17 panoramic fixed lens camera. These were well regarded at the time, with excellent lenses and sometimes quirky bodies (sound familiar?) I had a pair of the 6x9 cameras, one with a 65mm lens and the other with a 90mm. The lenses were ooutstanding. The handling of the cameras left something to be desired. But overall the results were very good 6x9 transparencies. Later Fuji made a zoom-lens version of the 645 camera.
It would not surprise me one bit to see a medium format version of the X100 style camera.