I already mentionned ganeti before when going over the LinuxConference Europe Schedule
Google just poste the news a couple of hours ago and you can go and check out the project on Google Code

Quoting from their site :

"Ganeti is a virtual server management software tool built on top of Xen virtual machine monitor and other Open Source software.
However, Ganeti requires pre-installed virtualization software on your servers in order to function. Once installed, the tool will take over the management part of the virtual instances (Xen DomU), e.g. disk creation management, operating system installation for these instances (in co-operation with OS-specific install scripts), and startup, shutdown, failover between physical systems. It has been designed to facilitate cluster management of virtual servers and to provide fast and simple recovery after physical failures using commodity hardware. "

You can use disk management using either plain LVM volumes, local-disk raid1 mirrors or across-the-network raid1 (using DRBD) for quick recovery in case of physical system failure

I`ll certainly be in the talk next week and I`ll be keeping a look on what happens ..