Tim; I've thought about this. Maybe others will add to my list?
A well constructed modular camera. Similar in build theory to the Red Camera, popular in the Cine world.
Modular updating of sensor, CPU package, battery management, that kind of thing. Upgrade your camera as needed. With a modular design, when chipsets become unavailable or obsolete, you just opt for a current unit. In the case of Red, the lens mount is available in C, Canon and Nikon. I wouldn't expect to see a big maker do that but, if modular, others may offer units that mate with the "Mother Body"?
As for profit, Red Camera seems to be very profitable. They just came out with a series of lenses and have been expanding their model system.
Expand on a known menu system. New cameras of a pro line, by a single manufacturer, should stick with a known menu system.
Be able to disable any menu items never used.. like "toy camera mode". Be able to disable any buttons on the body that aren't used. If I don't use Cine, I don't want to bump the button. I want it off, all the time.
I'm still thinking..
http://www.red.com/builder