When I read about this 1 week ago, and the NDA Robert Scobble had to obey, I thought that what Microsoft is going to show is going to be huge. After I watched the video presentation at TED I am dissapointed. Maybe my expectations were too high but from the video it seems that this software is not able to do much more than pan and zoom :) . I would go as far as saying that I am still more impressed with the animations and the tours that you can create in Celestia which is and old opensource software which runs on every OpenGL enabled computer OS and creates amazing graphics. The difference between WorldWideTelescope and Celestia is the fact that in one you get the images by downloading them at the time you are doing the zoom and in Celestia you already have the images and objects downloaded as textures. Without actually seeing the software would be wrong for me to go any further with the criticism but I will say that most probably this software is not going to be much better than Google Sky.  Also I am sure that the marketing money of Microsoft will prevail this time.