I saw some videos of Chrome OS running and I am not impressed. The OS looks a whole lot like their Chrome browser with tabbed operation. Well, I do not like the idea of having to open up a series of tabs just to have a couple of programs open. I want an OS to perform like an OS separate from my internet browsers. I can see Chrome OS coming in handy for people who don't want to fire up a full blown OS (such as a Linux variant, Windows XP/7, etc.) just so they can surf the internet. However, given the performance of Windows 7 (which takes about 25 seconds to fully boot on my netbook and 2 seconds to to come out of sleep mode), I see no need for an OS like this.
However, I can see Chrome OS coming in handy for portable devices as another alternative to Android, a watered down Linux variant, or Windows Mobile.