Microsoft has added some more Theme packs for Windows 7 collection as it has been doing , releasing nice themes from time to time.
They have recently released :
Echoes of the Past theme -
Time-travel back to the Age of Steam with a treasure-trove of antique images bathed in a golden Victorian light.
Classic Manga Action theme -
Get moving with colorful action-filled Manga illustrations by Ghy Kurabayashi and Steve Sampson .
Beautiful Birds theme -
Let the grace and gorgeous plumage of swans, flamingoes, peacocks, and other exotic birds brighten your day with this free theme for Windows 7.
For more themes Please check http://windows.microsoft.com/en-us/windows/downloads/personalize/themes