Privacy concerns return with an option to subscribe to updates from people or public figures, even if you're not friends with them.  Twitter-like functionality without the pseudonymity; but with increased control over the amount of updates presented and (fortunately) an option to opt-in to the subscription implementation.  An interesting move for Facebook, as it undercuts the social significance of generating circles of friends in favour of becoming a dormant follower.  Much like Facebook Groups, this is probably going to be left at the wayside in favour of the grown habitual uses of the social network.