Pull the sensor and processor out of the body and what do you have left that's of value? Not a lot - lens mount, LCD screen, ....
And if you go take that approach to upgrading what happens if someone has a better idea that would mean adding an additional dial or switch?
And think about the cost of returning the body to have the upgrading done by an approved Leica tech....
Actually the body would consist of most everything that defines the camera, except the detachable back which would contain the sensor, processor and probable the LCD screen. The body would include the shutter, aperture controls, lensmount (with communication contacts for new lenses, old lenses would still work manually), viewfinder w/rangfinder, and all the other relatively timeless mechanical and electro-mechanical features that are included in the body currently. The back would be the only upgradable part of the camera. Think about it, you could have two or more backs, a full frame for general and wide angle use and perhaps a more specialized back (say a 1.6 crop factor sensor for telephoto). You could have one back upgraded to the newest sensor/processor package with the 10 F stop dynamic range, very low [email protected]
ISO and 20G of resolution, while you were content to use your lowly "backup" back until leica returned your new toy. Makes me cream.
The key here is to "future proof" the heart and soul of what makes a leica a Leica, without comprosing performance in any way. Preserving that legendary shutter sound, the silky smooth focusing and controls, and that feel... that feel, is essential to justifying the high cost required to produce such a camera.
Leica buyers, though willing to pay a high price for their tools, can not be expected have anything but the very best. Granted, a rangfinder camera does not have the flexibility of an SLR, put for the nitch it serves, it serves very well.
Of course later bodies could have autofocus and other goodies not offered in the initial body, but this would in no way obsolete the first body. In fact, many would prefer an all manual body even if a more automated body was available.
Of course their isnt much chance of this happening.