There are already emulators that work in JS, that said, I don't know that it'd work for anything not emulated... As much as I love JS, I'm even a bit of a fan of electron based apps. That said this kind of integration doesn't make as much sense to me, it's interesting, but don't know how far it should ever go.
I can se leveraging web/js as part of skinning/theming a window manager ui, but not sure about having it this far down the rabbit hole.
For the "bigger" embedded platforms (rpi and similar), node is pretty serviceable... There have been other efforts to get JS based engines working well too. It depends on how you define embedded.
I was a little angry with my browser so that was meant to be an insult.
JS (not node) is usable for embedded coding. An example would be http://www.espruino.com/. Newer boards that come on Kickstarter typically support JS since it's a great intro language for coding especially for kids.
It's funny, but I like JS a lot, still think that Python is probably a better learning language... there's enough sharp edges in JS, that I don't think it's great for starting with, other than it's accessible, and combined with a browser, close to instant gratification.
I think it's great in the sense that you can easily make apps, games etc. which is good for getting kids interested quickly. Once their hooked, we can push them to some of the "better" languages.
As long as Python actively refuses to support real constants among some other immutability related features, I think the more recent versions of JS are going to get past Python in sheer elegance of code.
If you're Microsoft with their Azure/IoT setup, it's already happening. I've been spelunking in their SDK and it makes me want to tear my hair out.
I'm working with Cortex-M0/M3 devices kicking bytes over wifi modems, and Microsoft believes a "device" is a desktop-class SoC with an Ethernet jack running Node.