There has been rumors that Fuj is working on a digital medium-format camera for a while know. I have no clue if its true, but I hope it is. If it is, this is the camera I hope they are working on.
A note on sensor size: I have come to learn that the difference between APSC and Full-Frame is so negligible that it makes no difference to me. I have no desire to go larger than APSC unless something close to full medium-format was an option.
This is the camera that I hope Fuji builds if they go MF. It is a simple rangefinder with a fixed 90mm lens, which is similar to 50mm on full-frame. It is simple, fast, fun, and would create a HUGE, detailed, beautiful, image. It would be an amazing camera to have in your bag for portraits at weddings and would make an excellent commercial photography camera.
This would have to be a pricey camera, I realize that, but if they could keep it under 5k it would be the most affordable MF camera on the market, and I think would sell very well. Plus it would be freakin cool.