+1  A: 

It certainly is possible, you can get familiar with the windows 7 taskbar api, I would recommend starting with the windows 7 taskbar developer resources.

Quintin Robinson
Taskbar automatically shows preview for window, but not for tab items.
Akash Kava
Yes, exactly, however the mechanism to control the previews generated as well as the items in the new taskbar context menu is all exposed through the new apis. In addition to the link I posted above you should checkout http://msdn.microsoft.com/en-us/windows/ee624070.aspx
Quintin Robinson
The new version of Windows Code API does include my requirements but they arent very great while implementing, but anyway thanks for your answer.
Akash Kava
A: 

Here is something to get you started! I know this doesn't cover your scenario yet but it is planned in part 2, so keep an I on these:

http://dotnet.org.za/rudi/archive/2009/10/14/anatomy-of-the-windows-7-taskbar-tabbedthumbnail-part-1.aspx

rudigrobler
Your link doesnt work !!
Akash Kava