I fear you are missing something here. The reuse of sensor technology for example from 7D to xxD, xxxD cameras is not a bad thing, but good business sense: Avoiding senseless investments in R&D.
But the sensor in the 1D-X is not the same as in 7D nor is the sensor in the 5D Mark III the same as in the 5D Mark II. It has a slightly higher pixel count.
The thing is that Canon felt compelled not to increase pixel count, but rather invested in making the rest of the camera better. This is what many people have been telling for years: Don't worry about pixel count only. Usually I have heard this from people loving their Nikon cameras.
Nikon came from a different situation, where they found themselves being limited mostly to just 12 MP for many years. It is surprising how often this is simply ignored by people praising Sony sensors in Nikon cameras. Of course Nikon must try to make up for what they must have perceived as a problematic restriction in previous years, while Canon was free to develop their gapless fullframe sensors, which now provide better pictures at the same resolution (except in Neuro's previously stated circumstances).
Don't forget that as a company you are in real trouble regarding 3rd party dependencies in case you have to use key components such as sensors delivered as it is from a competitor. It does not matter here, if a generation of these sensors is especially good or not. This problem is much more severe.