To date, Sheen is known to the mass market for his portrayal of Tony Blair in both The Queen and The Deal, and he will next be seen as David Frost in Frost/Nixon. He’s best known to horror fans, however, as the Lycan Lucian, whom he’s played in all three Underworld films. No word on what role he’ll have in Alice, but I’m guessing it won’t be a key political figure or a werewolf.
Johnny Depp is on board as the Mad Hatter for Burton’s film, and we’re still waiting to find out if Helena Bonham Carter will be joining him. Actually, it’s probably more of a “when” than an “if”.