I was wondering if Canon would ever do such a thing or would the 1Dx sensor make more sense? Economies of scale already tells Canon to make the same APS-C sensor for every crop body, so why should the FF camp be the exception to the rule?
Logically, Canon would only have to produce 3 new DSLR sensors:
18mp FF (1Dx)
36mp FF (5D3)
XXmp APS-C (7D, 70D, t4i)
If canon will eventually bring us an enthusiast FF, the 1Dx sensor or the old 5Dii 21mp sensor has gotta be the most cost effective choice, because why spend more money on development?
This is all hypothetical and fun to do, but what does your crystal ball predict???