Marvel have been very smart in easing audiences into the more loopy elements of their fictional universe. The first film they properly produced was Iron Man, a character whose "powers" came entirely from technology and whose stars were all tragically human. Captain America was a pulpy adventure film in the Indiana Jones vein, and then things got a little more crazy with Thor - although you'll notice the majority of that film took place on Midgard, rather than in the mythical Asgard. That's why everybody freaked out when Guardians Of The Galaxy was released and suddenly the entire cosmos was open, with aliens and spaceships and everything. One aspect of that loopy universe that has yet to be covered, however, is the more mystical or "spiritual" side. Marvel's whole deal so far has been making relatively grounded features, with characters who are either human or definitely look pretty human, and certainly act like regular people. Doctor Strange, meanwhile, is all about magic and travelling to the astral plane and a bunch of hippie-dippy stuff that's not even been hinted at in the pretty realistic sci-fi flicks they've made so far. How they handle that transition could be interesting! Or else the magic will be described as "like another version of science" or something.
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/
