Explore the universe!
I always thought it’d be cool if someone combined Google Earth with Celestia. This looks like the first step.
Ooooh!! Ok, now I have to check out Celestia; thank you!
The current version of Google Earth has some of Celestia’s functionality.
Wow, this rules! (But where’s street view? :p)
Agree. I’ve got this on my G1 phone. It makes my iPhone-toting buddies jealous!
They could do a lot better job with flatfielding, to make the edges of photographs less obvious, and I’d like to be able to change coordinate systems, though that might be asking too much of a web-based application.
I’ve noticed this before with Google: They’re probably the best there is at dealing with information in general, but for specialized applications, you can get better results from specialists. In a similar vein, the Arxiv or the Harvard-Smithsonian Astrophysical Data Service are much better for finding astronomical papers than Google Scholar.
And why can’t you zoom in closer? 
Google lost a privacy lawsuit from Betelgeuse.
How does Google Sky compare to WorldWide Telescope? (My PC is old and creaky, so I haven’t tried either of them.)