The Official Google Blog has gone official with an OS release. Google Chrome OS is a light weight PC operating system that will be open source and targeted at netbooks initially and full sized desktops soon. It will be available to general public in second half of 2010. Get ready for the Beta or special invite to test it anytime soon.
Google Chrome OS is built to run on both x86 architecture chips and ARM chips ( netbooks ). Google has laid the groundwork already with the Google Apps Suite ( Gmail, Docs, Calendar, Spreadsheet, Reader etc ) with offline mode with Gears. Stay tuned.