Yes, Google can cache app sessions and data, and enable a system to function offline. But let's be clear: Chrome OS represents a lot more reliance on the Internet than Windows, Mac OS or other brands of Linux do.
For example, Google seems to imply that instead of drivers, Chrome OS will connect to devices via the Web. Lose Internet connectivity? You can't print!
Michael Jackson died, and the entire Internet nearly ground to a halt. In mid-May, most of Google's own services were completely unavailable for an hour. And even when the Internet and Google servers are functioning normally, the local connection to the Internet can be shut down for a wide variety of reasons.
Total reliance on the Internet is all fun and games until that connection is lost. Then what?
The choice between a desktop PC OS and Chrome OS isn't like the decision between Windows and Mac OS, where each option involves exclusive hardware and application software.
On the one hand, you'll have Google Chrome OS, which runs standard browser applications. On the other, you'll have OSes like Windows and Mac OS that run the whole universe of desktop applications and games -- and also run standard browser applications.
In other words, you're not choosing between a car and a house. You're choosing either both a house AND a car -- or just a car.
Several companies have spent years building truly great flavors of Linux. In what way will Chrome OS be superior to Ubuntu?
Has Google somehow discovered the missing ingredient, the feature that all those companies have missed all these years? Their claim is that they have: The main difference will be that it won't be able to run desktop apps. That's not a very compelling difference.
Remember when Google's Android was going to "kill" the iPhone? Dozens of phones were supposed to have flooded the market by now, each with wonderful, network-centric features. Fast forward to today, and there are just two phones supporting Android, and the iPhone dominates them both completely.
Google says we should all expect Chrome OS netbooks in the second half of 2010 and sometime later in desktop PCs. If the Android hold-up is repeated, we'll see one Chrome OS netbook by Christmas, and the second one by Christmas 2011.
Meanwhile, Windows, Mac OS and Linux will all be that much more mature and advanced.
Evolution happens, and some of my reasons for why Chrome OS won't automatically kill Windows could change. But by the time they do, both Microsoft and Apple will have changed as well.
The WIMP user interface (for Windows, Icons, Menus and Pointing Devices) is 36 years old now. The next generation of user interfaces will look a lot more like the Apple iPhone, with multi-touch, physics, gestures and 3D. These PCs will require scads of power and serious operating systems. Google may keep up, but the reason for the Chrome OS's existence will be diminished by this new world of computing.
I'm not saying that Google Chrome OS is bad, or that Windows is good. (I'll be accused of that, regardless -- please comment in the section below.)
I'm saying that current facts about actual human behavior, industry trends and history, as well as facts about what Google is actually proposing, don't support the conclusion that Chrome OS will "kill" Windows.
We should all welcome the competition, and wait with anticipation as Google presents its initiative. But any claim that Google OS will succeed is based on nothing.
ALSO SEE: How Google will Fumble Chrome OS