I've actually got a somewhat minor request in addition to the other ones I've conveyed over the months:
Music Groups!
Currently the music listings are structured to only allow one set of music to be played for a given level, with the exception of one elevator track which is managed via alternative means. I think it would be a nice asset to certain maps if they could dictate the type of music that a player hears at a given location/time. This could be accomplished in a manner similar to the "No Music" command currently used in some soundscape files.
While this would require a slight restructuring of the music script files, most existing ones would not need to be modified. The needed changes mostly require that in addition to the standard "music" grouping, there would also be additional groups titled "group1", "group2", etc. anything listed under "music" would play by default, only switching out if one of the other groups is triggered. This could be done with a line in the soundscape file, one that designates the music group to switch to when a player triggers the soundscape.
If this could be managed without great effort, i can think of a few maps that would gain a nice boost in atmosphere by using it. While it may not seem noticeable at times, i think our music is one thing that gives us a huge edge over other titles, so it's important to get as much out of it as we can!