Pixel OS. Lets dig in and take a look at what the hubbub is all about.
First of all, contrary to much of the misinformation by the BBC, Guardian, and others, it's not an OS.
It's an alternative DE (Desktop Environment), much like gnome, LXDE, and others, that sits on top of a linux OS. That's it, nothing more.
As a DE, it's lightweight (needed for limited resource machines like the Raspberry Pi), and very pretty. It's fully available for the Raspberry Pi, or you You can download an image bundled with debian and try it in preview mode on a intel based pc. Preview mode? Yes, you cannot install it on your computer, as it's a "developmental beta", not an installable DE.
The good news? Eventually it will be a usable option not only on the Raspberry Pi, but other platforms like Intel based pc's. Eventually.