It is a way to stay in the media.
More here
If you want to test it and give Microsoft feedback you can download and install the preview version from:
http://windows.microsoft.com/en-us/windows/preview
You should have a separate PC for that. For some reason I got this message:
..so you will be needing the Windows operating system to download and install this one.
It is not a standalone OS - you need to ruin a working Windows installation by the looks of it.
If you do so; you will get all of these benefits: