Leaked Windows 8 wallpapers on the web confirms that Windows 8’ll have user picture tile on taskbar with options to access control panel and logged in user’s account settings, you can to get that User picture tile on Windows 7 taskbar with help of a free tool called Taskbar UserTile.
Taskbar UserTile helps to get Windows 8 User Picture Tile in Windows 7. Download Taskbar UserTile archive, extracts its contents to a folder in your Computer and run UserTile.exe file.
From now onwards you can access control panel and, User account settings right from Windows 7 taskbar by clicking on User picture tile.
Taskbar UserTile is freeware and still in alpha.