I often just glance over my activity feed when I am doing work, and see my friends listening to a whole variety of tracks. I think it would be a great idea, if you could go directly from the Activity Feed, to the location your friend is listening from so you can see what else they are listening to, or listen to the same thing.
Obviously, there is privacy concerns with this, so the "arrow" shown below should only be displayed when the person is listening to a public playlist or from an album/artist page (and they share their activity). It would be similar to the "Listen with" functionality when signed into Facebook, but would not be synchronized or require you to go to Facebook!
I would suggest something like a small arrow (this is as small as I could make it in pain) in each entry in the activity feed which would take you to the playlist/page the track is being played from:
Currently when you share a playlist to Facebook/Twitter, it shows in your activity feed (and that of your followers) like below:
The numbers shown, in this case "5" and "11" correspond to the number of followers the playlist has, although that is made in no way clear when you view the Activity feed. Since it is not possible to view all of the playlist followers anyway (clicking the number does nothing) I think it would make much more sense to display the date/time that the playlist was last updated.
I feel the social side of spotify is somewhat lacking at the moment. Firstly, I can't connect with my Twitter friends, who, let's be honest, have much better music taste than my facebook friends, who are mostly people from my high school that I never spoke to. Also there doesn't seem to be a way to find anybody that's not one of your Facebook friends. There should be a way to search for people who have Spotify accounts, regardless of what other networks they're on. It seems like the only way to find people is to search 'spotify:user:usernamehere' which isn't really the most intuitive, and requires trial and error to guess what their username is.
I think the 'People' tab should show a list of people that you're subscribed to, with a stream of activity showing playlists they've made, albums they've listened to etc. and perhaps the ability to post statuses: recommending songs to your 'followers'. Which brings me to another point. There doesn't seem to be any way of knowing who is subscribed to you (as a user, not just a certain playlist). How many 'subscribers' do I have, and who are they? I guess some of these features may be in there already, but if they are, it's not obvious or easy to find.
I think these features would really help make Spotify more engaging, which would be useful now that Rdio is a competitor in the UK, and does social things very well.
Please bear in mind that the Community is not an official Spotify support service. It's a place where we all help each other, whether we work for Spotify or not. So please use your discretion when using the forum.