Today starts the Ubuntu "Reduce the delta with upstream" week where we will spend some time to clean up the packages changes and to send upstream the patches that should go upstream. The desktop team has created a wiki page for that, you might be interest to have a look on it and give a hand to update it (other team might be interested to do the same).
If you want to participate or have any question feel free to join #ubuntu-bugs on freenode (or team specific chans like #ubuntu-desktop). We also welcome upstream wanting to talk about changes we do to their application! (Vincent if you read that, are you sure you still don't want that gnome-panel "add to panel" patch upstream? ;)