That career, by the way, has him wielding the rather enviable job title of "Sorcerer Supreme". Constantly described as "the mightiest magician in the cosmos", Doctor Strange is blessed with so much power (and a whole host of enchanted ephemera) that he's essentially the most powerful character in the Marvel universe: able to travel between different planes of existence with ease, blessed with the power to alter reality and cast powerful hexes, and a pretty sweet outfit to go with it. Plus he's a bad hand with the martial arts, which comes in useful. At least, whenever he loses track of the the Cloak of Levitation which enables him to fly, the Eye of Agamotto whose light is used to negate evil magic, the Book of the Vishanti which contains knowledge of white magic, and the Orb of Agamotto which is used as a crystal ball. When he debuts in the Marvel Cinematic Universe either he'll have to have those powers seriously nerfed or else there's not going to be much use for any of the other heroes - Thor is a literal God, and even he can't bring the smackdown as much as Strange.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/