Google is going to share information on their upcoming Chrome Operating system on Thursday morning at Googleplex HQ in Mountain View, California.  They'll be giving a complete overview of the OS as well as technical background and some demos.
Word came out a few days ago that either part of the ChromeOS were going to be released this week or full early versions of the OS were going to be revealed.

The OS is widely believed to be an optimized version of Linux that focuses mostly on the browser and light web apps.  Google's other services like Google Voice (with Gizmo5 VoIP), Picassa and maybe even GDrive may make appearances but, just like the name says, the focus of the OS will be on the Chrome browser.

Writing, and getting manufacturers to write device drivers has been the biggest hurdle in getting the OS out the door so far.  Google initially plans on focussing the OS on Netbooks, specifically as an alternative to Windows XP/7.  Eventually they expect to widen the scope of the OS, porting it to larger machines.

The Google ChromeOS  is expected to be delivered in finished (or maybe Google's famous Beta™) form early next year.