Your Guide to the Latest Windows Server Product Information
Jeff Woolsey's 5-minute demo of Longhorn and Viridian (the virtualization feature of Longhorn) has been posted to the public site under "Spotlight." Some of you may have already seen this demo on Soapbox. The demo also showcases Server Core of Longhorn, Linux guest VM support, and support for 8 procs.
On a related note, I recommend reading Dave Northey's 3-part blog series on virtualization. Part 1 starts here.