Chrome OS is a brand new free operating system built around the revolutionary Google Chrome browser.

The project aim is to provide a lightweight Linux distribution for the best web browsing experience.

Featured software in Chrome OS:

• GNOME 2.24 desktop environment
• Google Chrome 4.0.207 web browser
• OpenOffice.org 3.0 office suite
• Flash Player 10.0 plugin
• and much more!

System requirements of Chrome OS:

• Processor: Intel Pentium, Xeon or newer; AMD Duron, Athlon, Sempron, Opteron or newer
• RAM: min. 256 MB
• Hard disk: min. 1 GB
• Graphics card: supports most modern graphics cards

source: About Chrome OS

There you if go. So if you want to have a taste on early development stage just head on to dowload page

They provided free virtual image appliance but You need a free VMware Player or VirtualBox in order to run this appliance.