"They are making a Magneto spin-off but I don't think it will involve me because it's about the younger Magneto, it's a back-story," McKellen said.
And what about the anti-aging special effects employed in the third "X-Men" movie? "Would I be willing to return to play a young Magneto? A cameo in my own movie? I don't think so," he said. "I don't think I could get away with playing a 19-year-old."
On the Hobbit front, McKellen WILL be reprising his role as Gandalf the Grey.