Probably not a surprise to anyone, but Zelda has been confirmed as a playable character in the new Super Smash Bros. She'll be retaining her Twilight Princess design. Presumably, her Sheik form will be back as well, though there isn't official confirmation of that, yet.
That's another recurring character dating back to Melee confirmed. At this point, all of the characters that I'd prefer return have been confirmed save for Captain Falcon and Samus's Zero Suit form. I'm more interested in seeing what other newcomers will pop up. How about you guys?