I think that separate mute buttons for music and in-game sounds should be available. I want to listen to my music, without having to mute the players' footsteps...
Just cosmetic, when in a certain area, it would be a good idea to slideshow two or three images. I don't think that that's going to make a problem with blizzard and it's going to feel somewhat better for the beginning stages, where you have to be close to the computer in order to play it.