After a pair of underperforming solo films, by current Marvel Studio standards, The Incredible Hulk proved to be a standout in Joss Whedon's Avengers team-up. Thanks to an increasingly believable blend of CGI and motion capture performance, a likable turn from Mark Ruffalo in the Jekyll and Hyde-like role, as well as downright crowd pleasing moments of Hulk Smash ("I'm always angry" and "Puny God" especially), the Mean Green Machine went from being a problematic standalone Marvel property to one of the studio's most valuable assets.
Still, despite ongoing rumors and unsubstantiated speculation that Disney and Marvel were planning to release a Hulk solo movie (specifically Planet Hulk) in Phase 3, studio executives do not seem nearly as confident in Hulk's solo potential as online scoopsters. Instead, Marvel is set to debut a series of new properties, including Doctor Strange, Captain Marvel, The Inhumans, and Black Panther, not to mention sequels to Guardians of the Galaxy and Thor, as well as a cooperative effort to bring Spider-Man into the shared cinematic universe - with absolutely no mention of a Hulk spinoff film. In fact, based on the current production slate, while we would expect the Green Machine to play a significant role in (at the very least) Infinity War - Part 1 & 2, the earliest that fans could get a Mark Ruffalo-led Hulk film would be 2020.
However, while fans might be eager for a full Incredible Hulk sequel, Ruffalo understands why the situation isn't as cut-and-dry as some viewers might think. Speaking to Empire, the actor explains that a solo Hulk story would be a tough nut to crack - while also giving some hope that just because the studio does not currently have plans for a Hulk movie, improvements in motion capture, as well as maturation of the character, could lead to one down the line:
It’s a tough nut to crack [...] Traditionally you’re watching a guy who doesn’t want to do the very thing that you want him to do. It’s hard to take for two hours. I don’t know how many times you can use that same framing for it, but now he’s maturing and there’s a cool dynamic growing between Banner and The Hulk. And the CGI is so much better. The stuff we can do now, you can do a real performance. I’ve been working with Andy Serkis [at his Imaginarium studio] and he has it set up where you go in there and you just start working on a character. It is so exciting to me, because I can do whatever I can imagine, with a team of people of course.”
While fans jumped for joy at the idea of a Planet Hulk movie, bringing the beloved comic book arc to life would have been incredibly difficult - since Hulk's time off-Earth was spent almost entirely in beast mode. Even Joss Whedon has described the idea of a solo Hulk movie as "tough" - without even addressing the added challenge of that movie taking place almost entirely in space.
Still, Ruffalo's comments seem to suggest it is possible that, several years out, Marvel could have developed a more streamlined (and cost-effective) process for translating the actor's performance into a finalized big screen Hulk. Meaning that the amount of Banner relative to the Hulk could be reduced - in order to explore the (occasional) antihero's more interesting and Hulk-heavy story arcs (including Planet Hulk). The actor also makes it clear that the interplay between Hulk and Banner is still one of the most rewarding aspects of his work in the MCU - claiming that the Hulk audiences will see in The Avengers 2 is more mature than prior versions:
“I think he’s definitely matured a little bit since the last one [...] He’s become more acclimated to this thing and to being part of the team. I think he feels more a part of them all. But in this particular take on it, it’s a much more character-driven version of The Avengers than the first one."
The actor teases an intriguing (and downright intimate) dynamic between the Hulk and Banner - one that comic book readers will certainly appreciate, specifically - that each personality will begin to bleed through to the other.
After all, a more intelligent Hulk and more reckless Banner would certainly help lay the groundwork for quality drama in a standalone adventure - as well as intriguing hulk out action:
"There’s a battle going on between these two opposing egos that live inside him [...] He’s definitely worried that the day is going to come when the Hulk gets the best of him, and maybe won’t release him, maybe won’t give him back. The Hulk knows this too. There’s a moment in here where he, begrudgingly, decides to go back to Banner. Who knows where these things will go, but as Bruce is able to impress his will on the Hulk, going into The Hulk and being inside the Hulk when he’s raging, The Hulk’s will is also growing and able to impress upon Bruce. That makes for some wild things. We’re laying the groundwork for that here. It’ll be interesting to see if that ends up being what would be the next Hulk movie.”
Without question, it shouldn't be lost on hopeful Hulk fans that Ruffalo directly makes reference to the "next" Hulk movie at the end of his quote - indicating that, even if there isn't a current film in development, the actor has likely had conversations with the studio regarding the character's development in both the immediate (The Avengers: Age of Ultron) and long term future (Phase 4). Of course, there's always the possibility that Ruffalo is merely using "the next Hulk movie" to indicate the next movie featuring the Hulk (after Age of Ultron). After all, rumors have suggested that the character could make appearances in other Phase 3 films (such as Guardians of the Galaxy 2, among others) depending on what happens in the upcoming team-up. Regardless, it's a safe bet that the studio isn't done with the Mean Green Machine yet - as the character should play a pivotal role in Infinity War - Part 1 & 2.
In the end, with over ten announced Marvel films that have yet to be released, it's probable that the Hulk will have further maturing to do before the character, and technology, can ensure success with a new live-action solo movie. Yet, the studio has made incredible (no pun intended) strides with the Hulk in recent years - clearly evidenced by Ruffalo's emotional "performance" behind Hulk's CGI eyes in The Avengers: Age of Ultron trailer.
There's no reason to think that, with enough time and resources, Marvel will bring the Hulk back for a starring role sometime in the future.
The Avengers: Age of Ultron releases in theaters on May 1 2015, followed by Ant-Man on July 17 2015, Captain America: Civil War on May 6 2016, Doctor Strange on November 4 2016, Guardians of the Galaxy 2 on May 5 2017, Spider-Man on July 28, 2017, Thor: Ragnarok on November 3 2017, Avengers: Infinity War - Part 1 on May 4 2018, Black Panther on July 6 2018, Captain Marvel on November 2 2018, Avengers: Infinity War - Part 2 on May 3 2019 and Inhumans on July 12, 2019.