That the video hosted on Microsoft Research's World Wide Telescope site is hosted with a Flash media player.
Can't somebody on the Silverlight team help them out a bit?
The WorldWide Telescope (WWT) is a rich visualization environment that functions as a virtual telescope, bringing together imagery from the best ground and space telescopes in the world for a seamless, guided exploration of the universe.
Sounds impressive though... can't wait to see it.
The best part about it. The dedication.
A. Microsoft Research is dedicating WorldWide Telescope to the memory of Jim Gray and is releasing WWT as a free resource to the astronomy and education communities with the hope that it will inspire and empower people to explore and understand the universe as never before.