With seven's new superbar, windows live messenger is now able to display your status on the bar's icon (and not on the system tray). So that got me thinking, maybe a firefox extension could do something similar.

Therefore, here's my question to those who understand the workings and spinning wheels behind firefox extensions: could a firefox extension change the superbar icon to display some useful info? Does the current functionality support it?

EDIT: I think my question is not really clear. I just want to know if it's theoritically possible for a firefox addon to change the superbar icon dinamically. For instance, windows live messenger changes the icon acording to your status, and gmail notifier plus changes the icon according to your unread messages count. I'm just wondering if firefox as it is right now supports an extension with that functionality. I know that no current extensions do it, and I'm not looking for a gmail notifier (that was just an example).

thanks