MSN Virtual Earth is only partially up (for example the UK isn't finished yet), but even now it is proving to be far superior to Google Maps.
For a start the navigation of the map is a lot better, allowing you to use your mouse wheel to zoom in and out. There is a little north pointing symbol that you can use to navigate the map smoothly too.
The satellite images on Virtual Earth are better because they allow you to zoom in just that littlebit more.
Space Needle on Google
Space Needle on MSN
More than that however Virtual Earth allows you to Plan Trips by keeping track of multiple bookmarks on the map and upto three search layers.
You can judge for yourself which is better, but when I see Europe on Virtual Earth and then on Google it makes me feel like Google is viewing the world through a small tube because Virtual Earth uses the full browser window.
One place of interest that is not recognised by either is Lake Bill at Microsoft HQ. Apparently some program managers like to swim the lake after a successful project launch.