Interesting question. I would argue that the Surface Laptop will drastically change the PC landscape over time. The people who use it this year will probably like it, comment on the limitations of only being able to use store apps, and recommend that people upgrade to Pro. And as far as the short term is concerned, that's a legitimate way to look at it.
The thing is, Windows 10 S, for which the Surface Laptop is the flagship device, is aimed at students. When I say students, I mean students of all ages. Think about it, Microsoft's hardware partners will build low-cost Windows 10 S devices that schools will be able to easily set up and manage and kids will interact with on a daily basis. Said kids will get used to using UWP apps as their daily drivers and developers will start converting more Win32 apps to take advantage of the market created by the Windows 10 S in the education sector. Over time, UWP will become the primary application platform on Windows, ousting Win32, and eventually replacing it completely. Now, the kids who grew up using Windows 10 S probably won't notice most of this, but that's actually a good thing because those kids will be the next generation of developers, manufacturers, business partners, etc. and so over time the PC landscape will shift towards Microsoft's vision of a "mobility of experiences" with Windows 10 and it's new Fluent Design spanning many form factors and interaction models. What I'm saying is that while millennials grew up with a mouse and keyboard and a video game controller, this new generation is growing up with touch, pen, dial, AR/VR, keyboard, mouse and whatever else we might come up with. Microsoft is uniquely positioned to provide a platform that the new generation can interact with in all these ways and I for one think that their approach is far, far more forward thinking than most people give them credit for. People see Windows 10 S and think it's Windows RT all over again, but the truth is that the future of computing itself if changing and those people are too stuck in their narrow mindsets to see Windows 10 S for what it really is, a computing revolution in the making.