They should also be able to make 1.6x sensors at least on par with those found in Nikon, but apparently they can't.
Wrong thread :-o but anyway:
"Apparently" - but appearances can be deceiving. The other possibility and the one I believe is that Canon doesn't want to because they'd have to invest more ¥¥¥ than they'd get a return of invest.
True, Sony has some important patents, but with the new 20mp crop Canon chose to go for other features like live view / video af and keep using their older sensor fabs/process. Why? Because *even* if the 70d sensor would be on par with the d7100 Nikon would still keep the more aggressive marketing and specs like af points, so why would Canon even want to try to match them here? They seem to be doing alright just the way they are, crop is "good enough" for mass production, ff for iq/low light.