Marvel is still in the business of collecting Hollywood stars.
Even though the film is not set to be released until November of next year, casting news for Doctor Strange has been met with fervid anticipation. After Benedict Cumberbatch, Tilda Swinto, and Chiwetel Ejiofor, McAdams has confirmed that she is in talks with Marvel regarding a mystery role in the upcoming film.
Time to speculate! Who do you think she'll be playing?
(If they come to an agreement, of course).
Princess of the Dark Dimension?
The fan-favorite right now is Clea. She and Doctor Strange have had an occasionally fraught relationship, but she's also a his disciple. Later in the comics, her power is actually greater than his, and she rescues him the way he rescued her at the beginning of their relationship.
This seems incredibly unlikely, but I would personally be interested in seeing McAdams playing Nightmare. The villain is one of Strange's major enemies, and is one of the first antagonists the hero faced. Marvel has already demonstrated that they're willing to go for genderbent casting with this film (Tilda Swinton is playing the Ancient One, who was originally a character presented as male). Since Nightmare is from a different dimension, this change wouldn't seem too bizarre.
We have a long time to wait for more solid news about this release, but that just means we have plenty of time to hypothesize!