I am a huge user of Google's many apps and resources. I also was lucky enough to receive a CR-48 Chromebook from Google to use and review. I really love how it works and think Chromebooks are an excellent idea for education. There is no support needed, nothing to install, it updates on it's own and you can do everything on it. All you need is an internet connection. Considering most people do everything online with web apps anyway, that's not a big deal. You can also have different user accounts and no data is stored on the device, making it great for sharing among students. The battery lasts a long time too. With all of the free web apps that exist, there is no need to license software either.
One issue that I did have was that I couldn't run Java apps so I couldn't run our gradebook software (from PowerTeacher). I just reviewed a new, free, app for Chrome called Rndr, that allows you to use Java apps on any device. I was able to use the gradebook on my Chromebook and now there is nothing I can't do with it.
They are becoming more popular and widespread and a great option for schools.
Here is a great video on what Chrome OS is:
Google Chromebooks for Education - updated pricing and info