Marvel Pictures is currently hard at work on it's "Phase 3" of movies to take place after Avengers: Age of Ultron. They are currently filming Ant Man, starring Paul Rudd, and are just about to begin filming Captain America 3. However, confirmations don't stop the rumor mill and we now have some possible news on the third movie of this phase, Doctor Strange!
At this time, it is being reported that Joaquin Phoenix is in the final negotiations to play the Marvel magic user. Doctor Strange is currently being directed by Scott Derrickson