This is what stands out for me:

"Live listening. While I decided to hide most of the UX I had worked on for launch due to it not being fully baked, if you're friends with someone and you see them "online" in your friends list, you can tune into what they are listening to in real time, and listen to music fully synced together. If they change a song, you change too! This is certainly alpha at this point though, but it generally works."

For those who are into 'social' listening, it's worth having a play around with.