I am very skeptical about this persistent talk that Nikon is at a disadvantage with respect to Canon because it colaborates with Sony to get good sensors, with the claim sometimes made that Sony just designs sensors in isolation and then Nikon has to just choose from the models that Sony has to offer. Firstly, Nikon is by far the largest customer for DSLR sensors from Sony's sensor division, far larger than the (persistently loss-making last I heard) Sony DSLR division, so even simple market forces mean that Nikon has a lot of say on the direction of Sony's sensor development. Add to that indications from well-connected sources like Thom Hogan that Nikon does to some extent share some of its technology in the design of sensors that are also partly designed and also manufactured for Nikon by partners like Sony.
Compare this to today's dominant example of a company that is heavily dependent on outsourcing components and design elements for its products: Apple, which indeed has spent the last fifteen years or so moving away from in-house manufacturing and designs towards working with the biggest, most efficient, most competent designers and producers of low-level components (like shifting to Intel processors), and using its volume purchasing power to get early access and best pricing on those components. Apple even works with phone-making arch-rival Samsung for many components such as screen panels and fabrication of processors for the iPhone and iPad. It has been argued that Tim Cook played a major part if Apple's revival and massive growth by his emphasis on moving away from doing too much in-house to more cost-effective out-sourcing where appropriate.
The examples of Olympus turning to Panasonic for help (by the way, its recent debacle is nothing to do with the camera division, but bad investments made many years ago and ten covered up by senior management of what is primarily a maker of medical equipment and microscopes) and Pentax bouncing from Samsung to Hoya to Ricoh simply, both show the impracticality of trying to go it alone in the digital era against competitors with far greater resources in the electronic side of modern photography. Canon is far bigger and better endowed on the electronics side than Olympus or Pentax or even Nikon, but still smaller and weaker than Sony or Panasonic or Samsung in that respect.
So it is unclear whether Canon has the resources to continue its DIY approach to sensor development. The trend of the last five years ago has been Sony starting from well behind Sony/Nikon in CMOS sensors and moving forward at a faster pace to now be signifiantly ahead of Canon! at least in the judgement of many observers.
Heck, if the Nokia/Toshiba/Sony/whoever team behind the 808 PureView sensor are really reading all 36MP of each video frame off the sensor for processing down to 1920x1080 on a second chip at up to 30fps, even that team appears to be well ahead of Canon in that respect of electronics capabilities. And that is what a Nokia engineer has explicitly claimed, with his talk of handling about 1.2 billion pixels per second read out from the sensor. Needless to day, Nokia could not have achieved that with an all in-house, DIY approach. Likewise, I very much doubt tha Olympus could have achieved the improvements in sensor performance and continuous AF capabilities touted for the OM-D E-M5 without a major (but as-yet unnamed) electronics partner.