We've been hearing for months now that the Russo Brothers are the front-runners to direct The Avengers: Infinity War - Part 1 & 2: the two movie event that will (for all intents and purposes) close out Phase 3 of the Marvel Cinematic Universe. More recently, a report emerged claiming that Anthony and Joe Russo had indeed closed their deal to helm the third and fourth Avengers films.
Today, Marvel Studios officially confirmed that the Russos will be calling the shots on the upcoming two-part Avengers "event" - based on the Marvel comic book storyline that will bring Thanos a.k.a. The Mad Titan's (Josh Brolin) ongoing quest to unite the Infinity Gems - and use them for his own nefarious purposes - to the forefront. The first two Avengers installments were written and directed by Joss Whedon (including this year's Avengers: Age of Ultron), but a screenwriter (or screenwriting team) has yet to be announced for the Infinity War features.
The official Marvel press release doesn't offer much insight beyond that, instead summarizing the Russos' ongoing contributions to the Captain America movies:
The Russo brothers first entered the Marvel Cinematic Universe with Marvel’s “Captain America: The Winter Soldier,” one of the top-grossing film’s from 2014, and are currently preparing to shoot Marvel’s “Captain America: Civil War.” The third film in the Captain America franchise will bring the classic storyline from the comics to life pitting Cap (Chris Evans) against Iron Man (Robert Downey Jr.), as well as introducing Black Panther to the Marvel Cinematic Universe with actor Chadwick Boseman ahead of his own film later in Phase 3.
Anthony and Joe Russo went from being directors known for their work on such cult TV comedy shows as Arrested Development and Community to becoming proper big name tentpole filmmakers, when they released Captain America: The Winter Soldier (a major critical/commercial success for Marvel Studios) a year ago. The Marvel powers that be knew they had a hit in Winter Soldier well before that movie hit theaters; for that reason, the Russos were lined up to oversee the third Captain America film, Civil War, ahead of the second installment opening in theaters.
Question is: can the Russos keep their momentum (read: their creative energy) and continue to match and/or exceed the quality of The Winter Soldier - going through at least three more Marvel Studio productions (each being an "event" of sorts, at that)? It's worth noting that the duo might well end up serving as producers on the upcoming Spider-Man reboot that will be included as part of the MCU - in addition to calling the shots on a Channing Tatum-led Ghostbusters spinoff, in between them making Civil War and Infinity War - Part 1 & 2. Give the Russos credit for ambition, if nothing else.
The possibility that the Russos will suffer from creative burnout by the time they work on Infinity War is very much a legitimate one, truth be told. Whedon has admitted that the task of putting together two Avengers movies (which, unlike the Infinity War films, released three years apart) was "enormously hard," which is partly why he's not directing the Infinity War films too. The difference is that Whedon scripted both of his Avengers features, in addition to directing; the Russos, by comparison, don't appear to be writing any of their upcoming directorial efforts.
No doubt, that will make a difference - not least of all, because the MCU is certainly becoming an increasingly complex web of overlapping plot threads and inter-connected storytelling elements. Meaning, whoever does wind up scripting Infinity War - Part 1 & 2 (probably not Whedon?) will have their hands full. They will have to organize not just everything that happened in Phase 2 of the MCU, but also the major developments that are planned for Phase 3 - into a coherent two-movie narrative that will tie a whole lot of story threads up. Best of luck, to the person(s) given that job.
The Avengers: Age of Ultron will be in theaters May 1, 2015; Ant-Man on July 17, 2015; Captain America: Civil War - May 6, 2016; Doctor Strange - November 4, 2016; Guardians of the Galaxy 2 - May 5, 2017; Spider-Man reboot - July 28, 2017; Thor: Ragnarok - November 3, 2017; The Avengers: Infinity War Part 1 - May 4, 2018; Black Panther - July 6, 2018; Captain Marvel - November 2, 2018; The Avengers: Infinity War Part 2 - May 3, 2019; Inhumans - July 12, 2019.