Feature Request for Firefox

Background, first: In XP, windows from the same application show up as one item in the task bar.  When you click that item, a popup list appears with buttons for each of the app’s windows.  These buttons are labelled with the title of the appropriate window.

Feature Request: When a Firefox window is not focused, I’d like Firefox to change that window’s title to be a summary of the tabs in that window.  That way, when I bring up the list of windows for Firefox from the Windows XP taskbar, I’ll have a better idea of which window has the tab I’m looking for.