Rayt
Nonplayer Character
I buy digital cameras when they are already "old" to save tons of money.
I will probably keep my D700 until it dies. It is just that good, even thought there are newer bodies with more/better specs.
If I ever get a digital M,I will keep,it until it dies too.
The idea that a D700 is an "old" camera is laughable, and an indication of how our mindsets have changed, and have been changed, since the advent of the digital age. I was thinking the same about my D3 -- same chip as the D700 just last week. The whole thing is farcical. But unlike your M2, which has been clicking away for 60 years and probably will for 60 more, our Nikons rely on proprietary batteries that will not be available (I speculate/predict) in 10 years or fewer, regardless of how the shutters are doing. Oh, they've got us now the camera companies. Phhhjoey.

IMO, barring the involvement of the insane safetycrats (read no more mercury batteries for our light meters), there will be batteries if there is a market for them. Capitalism has self-balancing component.