This idea has been suggested a couple of times. There are quite a few problems with this.
Firstly, sound files can clog up a website and slow it down. If people who are still on a Dial-Up connection want to surf quickly through peoples profiles, waiting for music to load probably isn't what they want to do.
Secondly, ArmorGames is a GAMING website, not a music or social networking website (such as MySpace and FaceBook.) It was made for the discussion and play of Flash Games, not music. If you want to discuss music with someone then I suggest using Myspace or Facebook.
if you want a playlist, just go make one at a playlist site, then post a link to it on your profile.
dude u can't do that btw I was just going to post something about this, I think it's a good idea, it explains more about u because it shows ur type of music, u could just say what music u like, like I did, but a playlist is better