Sony and anyone else are welcome to their 36mp sensor. Canon will continue to do that they are good at: producing cameras for photographers. Any more than 24 mp on a FF sensor and I would want a larger format to go with it.
disagree. Right now, Canon's full-frame offerings are lagging nearly a decade behind their crop bodies in terms of absolute resolving power. If you're shooting photos from far away, the reach of a crop body can't really be matched with a full-frame camera. You end up with barely an 8 MP image by the time you crop a 5DMk3 image that far, and less than 8MP for the 6D. Clearly, if 20 megapixels in a crop body produces usable pictures, then a full-frame camera with the same pixel density would also produce usable pictures.
Just out of interest, is there anything in the Sony sensor fabrication that makes it more feasible to have and use 36 mp on a FF sensor size compared with the Canon process ?
There shouldn't be anything impractical about it sensor-wise even with Canon's process. A full-sized sensor has around 2.6 times the surface area of a Canon APS-C sensor. Given that the 70D has a 20.2 megapixel sensor, there's no fundamental reason that Canon couldn't use exactly the same process to build a 52 megapixel full-frame sensor.
They might have to do some interesting work to actually read that many pixels out in a timely manner, and it would likely require a lot more CPU horsepower and faster flash cards in order to be usable. They might even want to do something like writing photos in alternation between two flash cards just to get the speed up high enough, but as far as I can tell, at least sensor-wise, the only reason Canon isn't way past 36 MP already on their full-frame cameras is either that they've decided not to do so for some reason or that they haven't gotten around to building the larger chips yet.
Oh, and yield issues, potentially. I don't know what Canon's yield looks like on the 70D sensor. For all I know, one in two parts might fail QA, in which case something approaching 100% of full-frame parts would be DOA. Mind you, I'd be shocked if the failure rate were anywhere approaching that, given that it is being sold in a relatively high-volume consumer camera, but you never know.