A new build of WorldWide Telescope has gone up, for both Windows and Silverlight platforms.
Grab it from here.
Cosmos view has been re-worked and looks a lot better, the Solar System view has had a view changes, eclipes now work on other planets, the Sun looks a bit better from a distance, although the planets all seem to still be spheres /facepalm I was really hoping that would get sorted in this release. There's also a bunch of new resources for tour creators (woo I had to source my own background music in the past).