Im sure all the major companies thought a lot about the format of the sensor,the majority staying with or near the 35mm format.The one brave enough to change this was olympus with its 4:3 sensor but are at a disadvantage because of its reduced size.Couldnt the 35mm frame have been sized up to a square to match the image circle of the lens and then cropped in post processing to whatever format you want.Personally Im a bit stuck with my leica but for anyone coming to digital as a new photographer the liberation of a formatless camera would Im sure be welcome,and fitting for a system so free from restriction and tradition.I do know of the medium format backs available,what Im alluding to is the non-existance of a formatless 35mm size camera and to the reasons why it does not exist.Ive recently been playing with cs3 and am both amazed and horrified at what it can do(my hours and hours printing and spotting prints made vastly easier and quicker,variations made with no cost,just interest,magic.)that now pp is almost as creative as photography,how nice to start with an un-camera influenced "negative", .......... maybe.