We've known the Follow tab and Discover tab would debut sometime early next year, but I'm eager to share what I've seen so far in the beta.
Perhaps most interestingly, I also stumbled upon a feature which was not been announced (nor was I told about it): Web Profiles.
They're bare bones right now, but suggest something major. Example: http://open.spotify.com/user/harrisonweber http://open.spotify.com/user/esquiremag