This defiantly depends on, what kind of person you are. To me, it sounds like a new version of Ubuntu or Fedora Core, but instead of being build over the Linux code, is instead build over the net. How they're gonna do that, beats me.
I don't think I'm ever going to use it. It doesn't suite my requiments of a operation system. If you use Google Chrome OS, you're a person you uses the net so regulary, that you're constantly online. If you use Mac, you're the kind of person who makes work your life, and media/sound is part of your work. If you use Windows, then you either have a lot of media, work or just a lot of computer games. Linux is best as servers.
It all depends on what kind of person you are, and what you need. I need a Windows, both for work and games. Therefore I'll probably never need anything else.
I'm not sure what to think about Google products
So the question is, what is it, YOU require from a OS?