I saw a post last week, someone mentioning that it would be nice to drag a bus in you project up into the track region, it would really only be a graphical thing, no change in the way it mixes in or anything sonic.
I think it would be nice to have a 'convert track folder to bus' option, with all tracks linked to that bus, and/or all tracks that were already in the track folder; acting like a track folder, bus it's a bus.....