When is Chrome not a browser?
When it's an operating system... one that isn't much more than a browser.
It's all a bit confusing to be honest but here's the rub:
Take Linux and strip it down to the bare essentials (including that all important browser), then hook it up to the Google cloud - like Cumulo Nimbus only fluffier - where you buy and run all your applications and store your data.
No user maintenance.
Low hardware requirements.
No cloud, no computing. WiFi is not ubiquitous (not even close) and wireless phone networks can be costly.
So why are Google positioning Chrome O/S for mobile devices? (Their testbed is a netbook with WiFi and CDMA 3G built in) They already have a perfectly functional mobile O/S in Android, capable of operating on phone networks over WiFi or standalone with no connection at all.
What Google has in Chrome O/S is an extreme lightweight operating system, the likes of which could turn every screen in the household into an impromptu web browser. 75% of US homes have Internet access, 45% have broadband and increasingly people want to connect more than one device to the internet, which means a router. Can you even buy a router without wireless these days? Guaranteed web access.
Remember when having a little TV in the kitchen was the big thing? Why not a WiFi-enabled LCD screen with a web browser to look up recipes, check the news, stream radio, music or television, even add items to your shopping list which you can later pull down to your Android phone (or any other phone/device if they're stored on Google docs). Make it a touch-screen and you wouldn't even need a mouse or keyboard in there.