Since the GNOME Volume Control UI sucks, I thought I'd play with creating some new UI for it. Colin says he likes it. ;). Images here, here, here and here. Not a real app (all Glade magic), but you get the idea.
The basic idea is to separate between input tracks (image #1), output tracks (#2) and option selections (#3). The input/output track separation is sort of logical, and decreases the number of sliders per page. The options need a different UI markup (vertical instead of horizontal) and are therefore separate; besides, as far as I know, they're not input/output specific. Picture #4 shows how to choose a different element (soundcard) for volume control.
Not shown on the images is the return of the preferences screen, where the user can enable/disable individual tracks. Disabled tracks will not be shown in the GNOME Volume Control main screen. Disabling some (maybe even by default?) should decrease UI clutter with many modern sound cards like the SB!Live, which make a total mess of volume control applications.
Of course, current-device and tracks-shown are both saved in GConf. ;).
I'll await some comments from random people who decide to call themselves UI experts and will then implement this for GNOME-2.10 or so. I hope Ross' GNOME-CD rewrite (based on Sound Juicer) makes it into GNOME Media then, which should make GNOME Media a lot better than it currently is!