Sir Ian McKellen has confirmed that he will indeed reprise his role as Gandalf in the new Hobbit adaptation that is being produced by Peter Jackson and directed by Guillermo del Toro. McKellen tells Empire Magazine, “Yes, it’s true. I spoke to Guillermo in the very room that Peter Jackson offered me the part and he confirmed that I would be reprising the role. Obviously, it’s not a part that you turn down, I loved playing Gandalf.”
Source: Empire Online