There are videos on-line already showing Live-Migration in action and I’m working on one to show how it its set up. In the mean time if you have the beta of server 2008 R2 there is a good guide on TechNet on how to set it up for yourself.

Of course I particularly like the fact that you can set up a cluster, with one line of PowerShell, And add a clustered VM with a second, and live migrate it with a third.  With clustering in Hyper-V server R2, and PowerShell in it, and in the Core installations of Windows Server AND the remote support in PowerShell V2 I like the direction things are moving in.