Microsoft has launched a new "Personalize your PC" website for users testing out the Windows 7 beta. If you're on Windows 7, you can get to it directly from the operating system (Right click desktop > Personalize > Get more themes online). The site currently has 15 themes, 13 desktop backgrounds, 8 desktop gadgets, and 5 SideShow gadgets (only for Windows SideShow-compatible devices). That may not seem like much, but the message at the bottom of the site gives a little hope:
Information about Windows 7 is preliminary and subject to change. Themes and wallpapers provided during this beta release are for testing purposes only. A greater selection will be available at the time of final release of Windows 7.
Personalize your PC Website http://windows.microsoft.com/en-US/Windows7/Personalize
Source: arstechnica http://arstechnica.com/journals/microsoft.ars/2009/01/13/windows-7s-personalize-your-pc-website-is-live