Marvel's remaining Phase 2 movies were the focus of the studio's 2013 Comic-Con panel. New footage from the Thor and Captain America sequels was shown at the event, but the highlights were the Guardians of the Galaxy segment - featuring the cast and raw footage from James Gunn's hilariously off-beat sci-fi vision - as well as the announcement trailer for Joss Whedon's capstone Phase 2 installment, which we now know is called Avengers: Age of Ultron.
Prior to this year's 'Con, there were rumors swirling around that Marvel would use its panel to announce at least one of the films that it has tentative plans to release in either Summer 2016 or 2017. That didn't happen, and the latest word from Marvel Studio President of Production Kevin Feige is that we shouldn't expect to soon hear an official confirmation of what films are going to be included in Phase 3 (besides the previously-announced Ant-Man and The Avengers 3, obviously) - at least, not until next year.
Collider sat down with Feige for an interview, prior to him taking the stage at the 2013 'Con. That discussion was heavily focused on Marvel Studios's future slate, and why Feige believes it's so important to keep taking risks in Phase 2 (and beyond) - with the next big "risk" being the Guardians of the Galaxy movie, since it's neither a sequel nor an adaptation of a widely-known comic book property.
To quote Feige on the subject:
"... So the need for the new is something we talk about, and we’ve been talking about for the past five years. Everything we’ve done has been a plan, has been premeditated. I love that Warner Bros. is doing it. I love that there will be announcements from other studios later today, about this notion of shared universes. It did not exist, and we thought it’d be fun to play with it.
"I love that our success has inspired people to do it, because the audience said, “we like that. We want more of that, please.” So, I love it, and I can’t wait to see those movies that come out. We’re not thinking three years ahead, even five years ahead and 10 years ahead. How do we keep it fresh? And Guardians is our big answer to that."
As far as additional Phase 3 announcements go, Feige said "It would probably be, at the earliest, a year from now [in 2014]." For the time being, the smart bet is that Thor 3 and Captain America 3 will be included as part of Phase 3 (in addition to Ant-Man), before Avengers 3 reaches theaters in 2018, in keeping with the three-year period between the previous movies (featuring Earth's Mightiest Heroes united together).
Therefore, when you consider Feige's comments about bringing new material to the Marvel Cinematic Universe - in combination with the unlikelihood of Iron Man 4 happening - it's reasonable to conclude that two new superheroes will make the jump to the big screen in Phase 3 (one in 2016, the other at an as-yet unspecified date in 2017).
Who might those two crime-fighters in question be? Well, Doctor Strange is all-but-confirmed, what with Feige continuing to name-drop the Sorcerer Supreme during interviews and those circulating rumors about what sort of actor Marvel wants to portray the character in his screen debut.
There's also been a fair amount of rumor-mongering and talk about Black Panther being part of Phase 3 (for example, Stan Lee keeps implying that a Black Panther film is in development). However, Marvel's co-president Louis D'Esposito recently alluded to T'Challa being a potential star for a Marvel One-Shot short film - meaning, a feature-length Black Panther movie is starting to seem more and more like something that's not be in the cards for Phase 3 (or the near future in general).
Inhumans, on the other hand, is a comic book property that has been part of the ongoing discussion since back before it was clear where Marvel would head post-Avengers. Furthermore, Feige has previously expressed his confidence that the relatively-obscure team of cosmic superheroes will become members of the MCU lineup in the foreseeable future (hint, hint), and one of the confirmed villains in Guardians of the Galaxy - Ronan the Accuser (being played by Lee Pace) - has a connection to the Inhumans' leader, Black Bolt, as far as the comic book continuity is concerned.
Lastly, an Inhumans movie being released as part of Phase 3 would be in keeping with Feige's desire to keep offering fans something new and fresh. The project would join Guardians of the Galaxy as one of the cosmic alternatives to the Earth-based MCU franchises (Captain America, Ant-Man), the half-Earth/half-cosmic nature of the Thor movies, and the possible new branch of superhero mysticism (Doctor Strange). We'll see, of course.
Thor: The Dark World opens in U.S. theaters on November 8th, 2013, followed by Captain America: The Winter Soldier on April 4th, 2014, Guardians of the Galaxy on August 1st, 2014, Avengers: Age of Ultron on May 1st, 2015, Ant-Man on November 6th, 2015, and unannounced films for May 6th, 2016, July 8th, 2016 and May 5th, 2017.