For now, the suggestions feature appears to be primarily focused on new Facebook users
Facebook just announced the availability of a new feature for users creating accounts on the social network: Suggested Interests. Facebook will now recommend that new users sign up for updates from ("Like") publishers with high reader engagement and subscribed-to by people demographically similar to themselves. That's unique combination of factors that only Facebook could offer.
If this intersection of 3 key social software trends is someday exposed more fully to all 500 million Facebook users and more - the Facebook vs. Google battle could become a fight between Recommendation and Search. Facebook recommendations are in the sidebar for most users today, but they are so powerful that it's worth betting they'll be center stage in the future.