Originally posted by sterretje Lowell, if you look at the titles that I gave the posts, you will see that I know it's hardware
the difference is, and I believe this is the intent of the OP (who I hope will comment), is to have customizable and selectable features on an existing camera, without having to modify hardware.
while some of your ideas may also have merrit, they would require new camera designs. and a change in camera layout.
Not that I wouldn't mind an interchangable back (or 5) for my PZ-1 with different full frame sensors as opposed to a film back.
The PZ-1 is in many ways still technically better than any of the DSLRS, with its 1/8000 shutter, 1/250 sync speed, fully functioning K mount, etc...
It would make an excellent DSLR starting point.