This November, Michael Sheen, whose performance as David Frost in Frost/Nixon impressed critics and audiences both onstage and on film, will undertake a somewhat different part – the leader of the Volturi vampire clan in New Moon, the sequel to the massive box-office hit Twilight. No telling if this choice of a part represents Mr. Sheen’s effort to compete with his co-star Frank Langella, whose best-known role, prior to playing the 37th President, was perhaps that of Count Dracula in a legendary Broadway tour de force later captured on film in the 1970s. But this is not the British actor’s first venture into playing otherworldly characters – he was a werewolf in the film Underworld and its sequel. (Indeed, there was something just a tad vulpine about his initial encounter with Caroline Cushing on a jet in Frost/Nixon.)