Christopher Eccleston, who played the Doctor in the first Season/Series of Russell T. Davies' relaunch of DOCTOR WHO, is set to portray Malekith The Accursed in director Alan Taylor's follow-up to Kenneth Branagh's THOR.
Per THIS piece at Deadline:
He is a super-villain in the Marvel Universe, the ruler of the Dark Elves of Svartalfheim. In the Marvel Comics, he clashed mightily with Thor, and will go up against the hammer-wielding god of Odin
Eccleston, who also appeared in HEROES and played Destro in G.I. JOE: THE RISE OF COBRA, is an amazing and diverse actor. His nuance and energy should be a staggering contribution to THE DARK WORLD, which hits theaters November 2013.