I think the most fun aspect of the all the Batman rumors hasn't so much been casting, but watching everybody try to nail down who everyone in The Dark Knight Rises would be portraying. For instance, Joseph Gordon-Levitt has been the subject of the most talk long before he had ever become a part of the Christopher Nolan's superhero production. Now that he's finally signed on, Variety is reporting that Gordon-Levitt will be Alberto Falcone, the son of former mob leader Carmine Falcone. Falcone was one of the many villains Gordon-Levitt was rumored to be taking on.
Tom Wilkinson portrayed Carmine in Batman Begins
In the comics, Alberto is sometimes referred to as the Holiday Killer, a serial killer who murders his victims according to specific dates on the calandar. He is featured in one of the best Batman stories you'll ever read, Batman: The Long Halloween
So in terms of new additions to the series, that gives us...
Joseph Gordon-Levitt as Alberto Falcone
Tom Hardy as Bane
Anne Hathaway as Selina Kyle(Catwoman)
Still rumored are Marion Cotillard in an unspecified role, and Juno Temple as a Gotham street girl.