The browser-based experience will run on top of the Linux kernel with a new window management created by Google. It's supposed to be virus-free, and it will work on both PCs and ARM devices.
I can't help but think the discussions we had in 2006 when we speculated about an "always online OS". The ideas seem to have caught on: you should be able to use your desktop, with your settings in tact (even wallpaper choice), no matter from which Chrome OS installation you login at through! Let's see if this is how it's going to play out. However, the question remains: would JS-based apps be as nice to use as native apps? The iPhone history shows us that people preferred native apps. Only time will tell.
Finally, have a look into an article we published here on OSNews even further back in time, in 2005; an article written by contributor Kris Shaffer. I got to hand it to that guy, he got a lot of it right, despite the negative comments he got for that article ("it's never gonna happen"). He got right not only the basic idea behind a cloud-based OS, but he even got the release DATE right!