Here are the officical videos from Google blog which will explain the Google Chrome OS:
What is Google Chrome OS:
Chromium OS is an open-source project that aims to build an operating system that provides a fast, simple, and more secure computing experience for people who spend most of their time on the web. Here you can review the project’s design docs, obtain the source code, and contribute. So just wait for more to come, its just the start of Chromium.