The Orion Nebula is a very famous spatial object and is often printed for posters. WorldWide Telescope contains vast imagery of this and many other nebulae.
Image used with permission from Microsoft. Caption by Wally Bahny.
The site looked like a dog's breakfast in Firefox, but also had to use the "Compatibility View" in in IE8 for the same reason.... are you kidding me??
"WorldWide Telescope is a new project from Microsoft Research" I don't mean to undermine your story, but this is not a new application at all. I have been using this for at least a year already if not 2 years or more. none the less it is an awesome application and does deserve recognition. I just hope that there's not a sudden influx of users that ends up slowing down the servers.
I'm a Windows user, but have to admit Linux/Unix are the dominant force in the science community, followed by Windows (too often XP!).
I first saw WWT demo'ed by Microsoft guys using a Mac. The message was clear -- WWT is built to run on many platforms. It can be used in a small (or large) school planetarium, or on your desktop. There are numerous scientists already using it!
Regarding both of the above posts - what scientists would be using this? It's a pretty-picture results display, not a form or framework for usable data.