Canon prides themselves on making sensors in house, and that is unlikely to change. They are expanding production. Its cheaper that way. Producing a large DSLR sensor is different from producing the tiny computer chips that Intel makes.Please correct me if I am wrong, but I was under the impression that Canon had already gone to newer and finer technology for it's p/s sensors.... To me, that indicates that the move is already underway.
Canon also produces the equipment to manufacture sensors and computer chips, so they can custom make their own equipment, they just have not yet decided to go to a new process, but it is said to be imminent.
Canon is making money while others are losing mostly because they are conservative and only make changes when there is a handsome payback. They are in the process of switching to 100% robotic camera assembly, so we can be certain that they believe that there will be a big payback. A new sensor packaging design has already been developed and is used in the SL1. Its probably robotic friendly and soon all Canon cameras will use it.
Does anyone know what technology is used in the fabrication of the 70D sensor? I would have guessed that the radical change to dual-pixel would have been the logical time to change processes.....