Both Canon and Nikon should consider this:

(All camera makers really)

the flagship camera models should be fully upgradeable systems, where you can send the camera to the shop and have them disconnect the whole back panel in one piece and slap on a new one with the latest and greatest technology, for a fraction of the price it takes to dump a perfectly capable mechanical marvel and replace it, just because the new consumer SLR has you beat in I.Q.

This way you pick and choose the time for your upgrade, without taking a big hit on your initial investment, and after so many upgrades, and when it's no longer possible to work the new technology within the older bodies, then a new model is introduced.

I think that could be very profitable, and will help strengthen brand loyalty.
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