Anyway to ruin the fun you guys are having, I think the Subject line is hyperbole. It's a standard Linux kernel they are running Chrome on, so it's hardly a new era in OS.
The effect of the product, if it takes off, is to move even further into the connected anywhere anytime model of use. The computer just becomes an information appliance. Your average consumer couldn't give a stuff if the OS was Linux or *BSD, or if the browser is Chrome or what. Those are just technical considerations that enable the features Google wants the product to have.
Eventually it will make the desktop model as archaic as mainframe computers seem to us today. Sure, mainframes still exist. Desktops will still exist in the future, but they will just be a small proportion of the computer gadgets around us. You phone is a computer, your media player is a computer, your TV is a computer, your car GPS is a computer, etc. etc.
M$ knows all this. Just recently they announced web versions of M$Office to try to catch the wave. Good luck to them.