Codename: Dashboard is, an application that resides at the side of your screen, similar to the "Sidebar" component featured in the now-infamous Longhorn video.
Built on the Microsoft .NET Framework, it is a host for interchangeable components. Through these components, Codename: Dashboard allows you to have any information you want, on your desktop, all the time.
More info:
hxxp://codenamedashboard.tech-critic.com/

Yes,

I have installed this one last week ;)

They release a new version every week. I wonder when will be the final version :)
Thanks Fisher!