There are so many different directions to go with this thread....First, I think the dual pixel was a great advancement for the consumer/prosumer level 70D. But, I am not sure the 70D was the target for developing the dual pixel system, but rather the EOS-M series cameras. Canon will likely drop the dual pixel system into the next generation of M to improve AF and have a potentially very nice second offering into the mirrorless market.
I don't see video as the growth market that others seem to think. Consumer and professional level video camcorders have been around for decades. Affordable video cameras at least 20 years. That was a defined, mature market. The "growth" that Canon experienced was stealing away users from that market, both professional and consumer, so that they could have stills and HD video from one unit....and also use Canon's lens system.
As for stills...this isn't scientific, but everyone I know that is into image capture (video or stills) is primarily into stills. This goes from age 10 to age 70. Not only are they into stills, but almost no one cares for video. I am not really sure why, but it just seems people (that I know) prefer stills. For someone like Canon to ignore stills would be like (to stick to the car analogy from earlier) an automobile maker ignoring the family sedan. Sure, it may not be the "growth" but it is still a very significant market.
Finally, regarding Canon moving onto new sensor tech because their current sensor tech is 10 years old....I hope they do. I would love more DR (as long as they still have good contrast). I would love the best sensor tech possible. But often, companies stay with what works until they find themselves in a competitive disadvantage or a new technology comes along. I hope Nikon/Sony has put Canon at enough of a competitive disadvantage so that Canon improves their tech, but given the sales numbers, I am not sure that is the case. Going back to the automotive industry comparisons....anyone ever look under the hood of their car? At the core engine? Sure there are add-ons and turbochargers/etc..but most car makers core engine has been the same for decades...that is...until something new came along...like hybrids.
So, I am not holding my breath for new sensor tech from Canon. They do have to figure out how to get people to upgrade from the 5DIII to 5DIV and 1DX to 1DXII. But that is 2-3 years down the road. Sure the 7DII may (or may not) come out sometime in the next year...but Canon could easily drop a slightly improved sensor into it, give it the 1DX/5DIII AF and 10-12 fps and call it good. Granted, I am hoping for new sensor tech