Microsoft has been releasing new Windows 7 Themes from time to time. Now it has released some more including the Fruit Ninja Theme and Nordic Landscapes Theme-
Fruit Ninja theme
The curiously addictive fruit-slicing game: You've got it on your phone, you've got it for your Xbox Kinect, now get Fruit Ninja on your desktop with this free theme for Windows 7. And watch out for those bombs.
Nordic Landscapes theme
An icy northern light falls on ocean cliffs, mountain landscapes, alpine lakes, and other scenes of natural Nordic beauty in this free theme for Windows 7.