Google launched a less than spectacular, yet brimming with potential, feature to Google Earth last year called "Google Sky". It effectively lets users turn the camera upside down to view the stars rather than cities. The idea is great -- just imagine using your computer as a telescope, or a perfect reference guide to real star-watching.
The problem with Google Sky, for me at least, are the icons scattered throughout the sky and the lack of a real reference point to the ground -- it's hard to know where exactly you are looking. However, like most things at Google, it will get better given time.
Rumor has it that Microsoft is about to launch some software that has been in the making since 2002[pdf] at TED this year. If reports are true, February 27 is going to be a day that Microsoft actually demolishes something that Google made -- it's apparently called World Wide Telescope.
Those who have seen it say that it's better than Google Earth (which isn't surprising) and Stellarium (which is). Stellarium is an awesome tool that has everything Google Sky is missing, and more.
If rumors are true, and if Google wants to win this modern-day space race, they are going to have to do something drastic -- but I'm going to bet that what you see is what you get for now.