launcher icons in panel become status

There are a number of comments floating around regarding the misuse of the notification area by applications such as pidgin, rhythmbox, banshee, opera and so on.
This problem becomes exacerbated when the user has launchers for said programs on the panel.. (waste of space, multiple icons representing the same program but performing different actions even though they look the same)

So, I propose an alternative: when launchers are placed on the panel, they should act like launchers until the program has been launched (for example rhythmbox), once launched it should replace itself with status information for the given application (for example rhythmbox: the music player applet displaying song title or controls or both etc.)...

so, practically this is music player applets behaviour already but it may be worthwhile expanding this kind of behaviour to other applications such as evolution or pidgin:

in the case of pidgin, launcher becomes online status icon

in the case of evolution, launcher becomes mail notifier.

I suppose what I'm suggesting here is the glue to put this behaviour together because these behaviours are perfectly possible (the music applet), just being displayed in the wrong place (the notification area for pidgin and evolution mail)
in the case of launchers being placed on the panel..

Any thought from others regarding this?