Muddiest Point #4

So, Google has a new browser out that basically moves the entire OS to the browser.  Looks pretty cool, doesn't it?  This only further muddies the conceptual waters regarding exactly what an OS does and is supposed to be, which is why I'm posting it.  Has anyone tested it out yet?  (I'm on a Mac right now, and Google doesn't seem to have it for Mac yet.)  My understanding is that this browser is basically Microsoft's biggest fear.