They also have datasets of 50M user profiles floating around out there filled with Facebook-like data. There still hasn't been a public leak of that kind of data that I can think of. I think a concern for Facebook is also what happens if/when 50M Americans' names, gender, hometown, birthday, and names of 500 closest friends become public for all to see. That's not really data that you can change or put back into a bottle.
The name and address data isn't anything unique. There's probably multiple companies with better address data than Facebook has. And the national party organizations have pretty much complete voter rolls with addresses.
The unique data is the friend graph and the likes, which they can use to (quite effectively) predict political attitudes.
