I think there will be a shift of people towards x86 laptops, but as someone said above, I don't think it will be much of a blip.
However, for those who are affected, it's certainly a big deal. I shifted to Windows when my 2011 Macbook Pro was due for retirement, but because of Apple's awful butterfly keyboards, I went with a ThinkPad X1 Carbon. After a year of use, that machine is doing me very well indeed (industry-leading keyboard, beautiful 4K screen).
But seeing as Apple had fixed their keyboards, I was pondering whether to go back to a Macbook Pro when this X1C retires. I do need to run some Windows apps for my job, and that was fine via Parallels. With ARM, it seems this won't be possible (that Linux build we saw running in Parallels during the demo was an ARM-compiled Linux distr).
So... looks like I'll stick with Windows. Fortunately, there are plenty of options, and I'd likely be looking at an all-metal laptop for my next one (the X1C is a fingerprint nightmare, and while the keyboard is the best in the industry, the trackpad is possibly the worse).
Those looking for all-metal Windows laptops with a trackpad comparable to a Macbook Pro would probably be quite pleased with a Razer Blade.