I think I need eventually needed to commit to installing kde and kudzu to install SDL_mixer (which I won't do ;).. I think that's too much commitment of diskspace just to try out tuxracer (in powertools). Perhaps the kde stuff can be splitout? into a dependent library? I would think that the kde aspects of xmms, SDL_mixer, could be put in a kde-sound-extras, as opposed to putting them into the base packages.
This can't be done because SDL supports both sound systems (arts and esd) by linking directly to the library, not by additional modules etc. xmms has been fixed (it comes with all the modules, but doesn't require their dependencies anymore); this can't be done with SDL because there's nothing between "compiled in arts support" and "no arts support at all". I'll try to split off arts into a separate package though, that should work for most people.