> > and backgeound music of some sort?
>
> Mmmmmmm... I would prefer, for example, listening to the demo noise of the
> nearest machine which has noises in the demo loop.
>

There's one implication there, and that's that only visible arcades are updated to save some CPU load (I have to steal some performance *somewhere* ;-). That's why the sound is disabled until you actually activate a game to play.
However, *some* background noise should be cool so maybe I'll add some generic arcade sounds in the background and/or music.