Well, that's a retro way to announce a casting...
Buried in the fine print of the new Doctor Strange trilar and poster released during Comic-Con International: San Diego this weekend is the name of Benjamin Pratt. Check it out:
Who is Benjamin Bratt? While there are several Benjamin Bratts in the IMDB database (including a crewmember who did rotoscoping and art prep for Guardians of the Galaxy), Bratt's name is listed among the actors - and the most popular actor with that name is Law & Order alum Benjamin Bratt.
No details about Bratt's role in the film are seemingly public, however, and the late back-handed nature of this reveal adds question marks about why Marvel Studios has been so discreet about it up until now.
Is it because he was in Warner Bros.'s Catwoman from 2004? Nah.