It would be insanely cool if we could have a DJ Booth at parties and, perhaps, even the ability to purchase one for our home (once we get the super cool house upgrades).
I'm thinking something along the lines of turntable.fm where users can choose from an existing database of songs or add their own. DJs have the power to play music and partygoers & listeners have the ability to say this is awesome or this sucks... too many sucks and the song is skipped. There are, of course, other possible setups and partnering sorts of options (Spotify with their library & player could be interesting). I just really adore what they've done with turntable.fm and think that sort of setup is extremely compatible with glitch parties & houses.
It could, perhaps, come with a skill and/or there could be various rewards for getting high ratings as a DJ (badges, xp, mood, drinks, etc).