In fact, because of Canon's market share and installed base they could quite easily remain one step behind the industry state-of-the-art in sensor technology and STILL maintain their position -- until and unless that gap truly and actually results in better photos, not just better specs, coming from the competition.
That's true, they're darn near a Juggernaut.
And all the gear these days is so good that no one bit of kit is going to stand out to such an extent that it makes the competition irrelevant.
It's only a few of us (vocal minority types) who prefer some of the technical advantages offered by the competition enough to add them to our inventory. Some of Nikon's and Pentax's gear makes my life a little easier vs using Canon. Altho it's unlikely we hold much sway with the likes of Canon; they're still making a (lot) of money doing things the way they've always done.
The competition had to improve substantially just to get noticed, IMO. I think they've accomplished this. Maybe they even improved their market share slightly.
But that consumer base is an important segment and I still don't see how that fight's going to change any.
I've heard more than one consumer type photog tell me that they've heard recent Nikon cameras are technically better but it didn't matter enough to them to buy one, their first SLR was a Rebel. And they liked it. And if any of them upgrade, they're likely to stay with what they know.
I think it takes more than just cash to switch to or add another system. It takes a degree of courage and determination. There's more learning to do, more things to remember. That sounds like work and we can predict what most people think of that.