I thoroughly enjoy the product available. My only wish is there were some way to link someone to a track through a URL. I regularly use IRC and other chat clients with people, if I want to share a song with a friend I'm currently forced to Google the track and then link a corresponding youtube video. Music being mainly about the rhythm really can't be enjoyed through youtube though, their service chops and hiccoughs which ruins the timing. I've never experienced that on Spotify.
TL;DR : give us a way to link playlists and tracks to people other than Facebook.