I use Joli OS on my netbook right now, and while I like it a lot it's a little annoying to use sometimes. Not everything I need is available as an app yet, and deleting/moving documents from the harddrive is tricky.
Chrome OS isn't the only operating system with its head in the clouds. Jolicloud's Joli OS has been around for a few years now, and it has a similar focus on web apps. It doesn't boot as fast or feature the same tight hardware integration that Chrome OS does, but it can run native desktop apps as well as web apps.