Look out Sony AR-7, Canon is comming ...

Lol. Of course this camera won't have dual card slots. No new model of Canon has ever had dual card slots. While if you are anxious about it you should definitely invest in a camera that has dual card slots ( solely for your own peace of mind - and the effect it has on your artistic output) for years and years as a professional wedding photographer I used single slot cameras. Using proper technique and discipline as a pro completely negates the need or even the benefit of such a feature, using both slots in my 5D 3s is detrimental to the camera's performance though. The key component is ensuring you have proper, high-quality, good condition, memory cards... Where the chance of and spontaneous complete failure is literally considerably less than being struck by lightning. There are many fakes, so what might seem like a good deal is off in a very bad deal, but that is completely avoidable.

I would even go so far as to say that if you are forced to buy one camera with dual card slots (almost universally more expensive) versus two cameras with single card slots, that is actually detracting from your ability to capture and preserve unreplaceable imagery due to the vastly more likely event of losing a camera in its entirety while shooting professionally . I can't even count the number of times I've heard local professionals lose a camera, it fell out of the boat, it went in the river, it fell off a building, it was stolen, it burst into flames, it went into the ocean, etc etc. Dual card slots aren't much help in any of those circumstances.... And every one of those circumstances is far more likely. A better way in my experience to prevent disaster is to carry and use two cameras interchangeably, while having the discipline to switch back and forth during shooting.

I may replace my current cameras with when the time rolls around, but it's going to depend on the handling, which obviously I haven't done yet. Qualms about switching from dual card cameras to single card cameras? None at all.

...otoh, IBIS is a feature I'd pay good money for...