Microsoft official Personalize Gallery has added 3 new themes to its collection. They all look pretty nice.
Theme Bing’s Best 2 contains 21 high-resolution wallpapers that have been used in Bing search background.
NASA Hidden Universe theme includes 14 high quality of space pictures taken by SPITZER Space Telescope. You may like them if you are a space fan who likes to explore the universe.
Surreal Territory Theme has 6 dreamlike landscapes designed by artist Chuck Anderson, who is the one that designed the Windows Logo, the you normally see as the default wallpaper of Windows 7.