While Joss Whedon's exclusive deal with Marvel is set to end soon, it had been widely assumed he would take on Avengers 3, if only to finish out the presumed trilogy that he'd launched in Marvel's The Avengers.
Now, with developments in the Marvel Cinematic Universe seemingly pushing events once assumed to be taking place in Avengers 3 out to a fourth film, Badass Digest reports that Joe and Anthony Russo, the directors behind Captain America: The Winter Soldier, could take on Avengers 3 and possibly 4 after completing production on Captain America 3.
The piece also makes some interesting observations about the future of the Marvel Cinematic Universe: first, that there are no secret identities to fight over, so Civil War will have to be somewhat reshaped in order to make "sense" in the MCU. Still, the idea that Tony Stark feels responsible for the events of Age of Ultron -- his purported reason for being pro-registration in the Civil War storyline in the movies -- makes more sense than the one they had in the comics.
Second, it's indicated that the story plays out threads from Age of Ultron and serves as an Avengers 2.5, in the same way Captain America: The Winter Soldier was jokingly called Avengers 1.5. The piece claims that The Vision will likely appear in the film along with Falcon, War Machine, Quicksilver, Scarlet Witch and Black Widow.
The article further reiterates a previous BD rumor that Chris Evans will sit out Avengers 3 following the events of Captain America 3. Whether that's because he's dead, as his character briefly was following Civil War, the story which serves as the basis for Cap 3, or some other reason isn't clear. It also says that the fallout from these films will "leave the world wide open" to an attack from Thanos in Avengers 4 or another universe-wide crossover film including the Guardians of the Galaxy, The Avengers and more.
Ironically, Civil War was written by Mark Millar, who has been described as "Fox's Joss Whedon" and has a major role adapting that studio's Marvel films, including the upcoming Fantastic Four reboot and a number of rumored X-Men spinoffs.