I love the new starred track feature. I wish it was possible to globally star tracks so other users could see them. The best would be "administratively" starred tracks in addition to your personal starred tracks. This way users unfamiliar with new albums good see tracks the host site recommends.
Also, I miss the shared global playlist from earlier versions. I liked to be able to create new playlists for others to use and vice versa.
These are sort of different sides of the same coin. I think shared stars and playlists encourages a more social media server.