Eh, what? I just looked at that Google excuse for a service and it's not comparable. The Hayden Atlas is not a web service. You download it and then use it. It's in real 3D and you can move around it as much as you wish and use various views which will tell you all sorts of interesting things and you can move out from the Sun and so forth. If you actually have a decent astronomy textbook, you could get even more out of it.
The Google Sky thing is.... *shudder*