The trouble with Chromebooks is that Google can't come up with a powerful ultrabook that costs $700 or $800 because people would think it's too expensive. Why not get an ultrabook that runs a full-fledged operating system and install Chrome?
To solve this issue, Google could try to change people's perception about Chrome OS and show that it's not just a browser. The latest Chrome OS releases made a lot of important changes: the browser can be minimized and resized, it's easier to open multiple windows, there's a desktop and a taskbar, you can change the wallpaper, there are cool applications like the media player, ScratchPad or Calculator that no longer open inside the browser. By including great applications that work offline (a dictionary, some games, a contact manager, a calendar app) and encouraging developers to build standalone apps that work outside the browser, Google could show that Chrome OS is more than just a browser.
That's what Google did. After buying Quickoffice, Google ported the mobile app to Chrome using Native Client. Right now, it only opens Office file in read-only mode, but it will soon support editing files. It's not exactly Microsoft Office, but it's a pretty good office suite that works offline.
Google also works on a Google+ Photos app powered by Native Client that will let you import photos from your camera or phone and upload them to Google+. The most useful feature: automatic selection of the best shots.
Chrome OS already has many features that live outside of the browser and it will add even more. Powerful Native Client apps that also work offline will allow Chrome OS to compete with full-fledged operating systems like Windows and Mac OS. Chromebook Pixel is Google's way of telling the world to take Chrome OS seriously. Chrome OS is no longer an experiment and a Chromebook is no longer useful just as a second device, it could become your main device.