Prolific radio host of Sirius FM Howard Stern, may have accidentally outed a Marvel film in the works through a hot mic incident. Howard is heard talking to one of his producers about his upcoming plans for the summer. Said plan apparently includes time being blocked off to cameo in Doctor Doom in some capacity.
Robert Downey Jr. also gets mentioned briefly lending further credibility to speculation. The Howard Stern Show gained popularity when it was nationally syndicated on terrestrial radio from 1986 to 2005. He has broadcast on Sirius XM Satellite Radio since 2006.
As reported by IGN, Howard said "Tell [Kevin Feige] it works, but They're going over the schedule with me, and it's going to suck ... I'm going to do 'Doctor Doom.' I called Robert Downey Jr. and I was asking him acting techniques"
All speculation will be put to rest during San Diego Comic-Con, set to start on 21 July, as Marvel Studios is confirmed to attend.