Dear Raid,
What improvements do you expect in an M9.2 or M10?
More megapixels (18 is enough for publication)? A different rangefinder? A different lens mount? Better manual focus? Better metering? More shutter speeds? What? Sure, higher ISO/less noise is possible, but again, if you're merely earnng a living with a camera, instead of buying bragging rights, how much more do you need than ISO 2500? Some do, perhaps, but not many. Likewise you can improve AWB and everything else; but an awful lot of buyers aren't going to care, because the M8.2 is already good enough.
In other words, likening an M9 to a computer, merely because both contain a lot of electronics, is facile and shallow. I really believe that it won't depreciate at anything like the rate of low-end consumer products, because it isn't a low-end consumer product and because it's aimed at photographers, not at computer nerds who play memory-hungry games on machines that are more powerful than those which NASA used to put a man on the moon.
Cheers,
R.