If i were Facebook
i will buy Last.fm.
create a ‘channel-app-like’, so we’ve got status stream (text), photos, video, and last but not least, Audio. that’s where Last.fm coming.
as we know that Spotify is already built in to the Facebook, it’s easier to integrate both of them. status flooding is something that many user would not love, so for the audio, the traffic will be huge, don’t bother about putting what other people listened into their wall. just don’t do that.