From a quick note I just sent to a friend pertaining to music and social...
My instincts about the future of any person's willingness to accept inputs into their social streams tell me that people are becoming fatigued by input overload.
Music and social go great together as long as the person you are getting the social music feed from is a filter that one can trust. For example, I have zero interest in the music my relatives consume; however I would not mind checking out some of the songs my producer friends recommend, as I believe they have the capacity to point out great new songs.
Going forward, I believe that people are going to become far more selective about what they feed out to the world; otherwise they are going to increasingly run the risk of being 'unfollowed' by their followers.
In my own world, I un-follow anyone that 1) tweets a lot, or 2) does not provide interesting links to relevant (to me) information. I just don't have time to sift through a lot of scribble.
Said another way, I am not a proponent of any service that tightly integrates with 'social' where the default state requires me to take an action to prevent my 'scribble' from leaking out to the world.
Hope that helps..