Here is an interesting post by Jason Jones at ProfHacker: Eight Thoughts After Trying the Samsung Chromebook.
Chromebooks are cheap ($249) netbooks running Google's ChromeOS to give you access to the Google 'ecosystem' of tools - nothing more, nothing less. That's not too different from the approach Apple took with iOS and its associated devices: here's the hardware, the OS, and the apps and we will make it impossible for you use anything else.
Full disclaimer: I have not touched or used a Chromebook, but it seems a rather limited option - for a couple of hundred dollars more you can get an inexpensive real computer. Still, Chromebooks may be an option when you want to restrict choices, but still want a computer with a real keyboard or mouse (as opposed to a tablet).
In that sense Chromebooks may be the 'happy medium' between providing each student with a high-end laptop or forcing every student to bring their own computer to class (aka a BYOD policy). Chromebooks seems to be getting more popular and accounted for 21 percent of notebook sales in the US.