What was earlier rumored appears to almost be reality. According to sources, Benedict Cumberbatch is now in final negotiations with Marvel to bring Doctor Stephen Strange to the big screen as part of Marvel’s Cinematic Universe Phase 3. Currently, Doctor Strange is slated for a July 8, 2016 release (only 2 months after Captain America 3) but the schedule is tentative, so all that could yet change.
Earlier reports indicated that Marvel was looking into Joaquin Phoenix for the role but that he couldn’t commit to a three picture deal.
In any case, I think Cumberbatch is an excellent choice for the role. Just look at his work on the BBC series “Sherlock” as the title character and try to apply that to the role of Strange.