Long story short: Marvel Studios can make a solo Hulk movie if they want to.
During the Avengers: Age of Ultron press junket, Mark Ruffalo told Collider he thought a standalone Hulk movie was being held up because “That’s still Universal’s property, so there’s that issue.” Now, Forbes has dug deep and come up with the particulars: Marvel has owned the film production rights to the Hulk since 2005 after Universal declined to move forward with a sequel to Ang Lee’s 2003 Hulk starring Eric Bana and thus allowed their license on the character to lapse. However, Universal still retains the right of first refusal for the distribution of any future Hulk movie, which is how they ended up distributing The Incredible Hulk in 2008. Theoretically, Marvel Studios could start making a Hulk movie tomorrow with no involvement from Universal, and Disney could negotiate to buy Universal out or come to a mutually beneficial deal. That is, after all, exactly what Disney did with Paramount Pictures, who were still on tap to distribute The Avengers and Iron Man 3 when Disney purchased Marvel Studios.
So, if Marvel Studios can make their own Hulk movie why aren’t they? Because The Incredible Hulk is their lowest-grossing film, and The Avengers showed he might be better off as part of a team.
Fine. Whatever. But remember how cool it was when Captain America told him, “Hulk, smash!” and then he went and smashed the Chautari. That was cool, right? That was just one scene, though. Couldn’t they give us a whole movie of that? Shouldn’t they make a standalone Hulk movie? Give the people what they want! Well, who would they have around to tell him to “smash”?
You can make a pretty compelling argument that despite Forbes’ report nothing has changed. Whether or not Marvel is holding back on the Hulk because of Universal or by choice doesn’t matter because it’s likely the right move. In fact, I hope nothing becomes of the back-and-forth Ruffalo has been having with the press as of late about Robert Downey, Jr. apparently giving him the heads up that he might be needed for Captain America: Civil War. No, do not put him in Civil War. The Hulk should remain an Avengers-only character, even if his absence from the other movies results in Joss Whedon somewhat forcing a Bruce Banner-Black Widow romance in Age of Ultron. The Hulk is one of the few things that makes the Avengers movies feel extra special, along with the novelty of seeing the solo characters (and Hawkeye and Black Widow) grouped together.
In truth, I largely do not know what story you would really tell in a standalone Hulk movie at this point. The most popular option is Planet Hulk. The Hulk is deemed too dangerous for Earth and shot into space by a group of friends who trick him, landing on an alien planet where he basically becomes Russell Crowe in Gladiator, forced into slavery and fighting in an arena for the entertainment of all. In the sequel, World War Hulk, he returns to Earth and gives The Avengers a taste of their own medicine. Many would kill to see Planet Hulk on film, and early reports indicated Whedon’s Age of Ultron script ended with Hulk in space thus setting up Planet Hulk, although clearly things changed at some point along the way. However, I’ve never really been a fan of the Gladiator storyline in sci-fi. Not when it was a vampire with a soul on Angel. Not when it was Seven of Nine on Star Trek: Voyager. And not when it’s the Hulk.
With Mark Ruffalo, Marvel has finally cast the perfect Bruce Banner, and the CGI has really come a long way meaning a new Hulk movie would look amazing. I just don’t want story there is to tell since Hulk and The Incredible Hulk sort of covered the basics.
Collider thinks they have two options:
You can make it a very human story – a Dr. Jekyll and Mr. Hyde tale – in which a mild-mannered intellectual grapples with a very real internal monster, or you can go big and put the Hulk up against foes who are almost a match for him, ie “Planet Hulk” or “World War Hulk.” In the first instance, we’ve already seen those storylines in previous films; they didn’t connect with audiences for a number of reasons. That’s not to say that the right story with the right actor at the right time wouldn’t work, but Marvel is likely not willing to take that gamble when the existing Avengers movies provide just enough of that plot to be rewarding to audiences in small doses.
As for the big-budget Hulk stories, if Marvel isn’t willing to spend the money on a more down-to-Earth tale, then they’re probably even more reluctant when it comes going to the other extreme. Putting an entirely CG character on screen for 90 minutes against an arena or world populated with hundreds of similar CG characters instantly starts to raise the budget while reducing any semblance of humanity in the film.
I mostly only know The Hulk from the movies. I’m only vaguely aware of the current animated series, Hulk and The Agents of SMASH, in which Hulk never seems to revert back to Bruce Banner and is joined by similar Hulk-like partners. There’s also She-Hulk, who is actually quite intelligent in her Hulk form, working as a lawyer! There’s an animated movie in which Loki uses magic to actually separate The Hulk from Bruce Banner, unleashing the former as a mindless monster tearing through Asgard.
In the live-action movies, at this point The Hulk is a supporting character, and maybe that’s for the best. He’s a really cool rage monster, and maybe Age of Ultron actually offers a perfect segue into a story with Bruce Banner on the run from both the law and anywhere he might hurt people. However, isn’t that also the basic story of The Incredible Hulk?
Maybe I’m showing my ignorance about the character’s long comic book history here, but is there anything more to The Hulk which demands its own solo movie at this point?
We Minored in Film 
I want another Hulk movie, but I also don’t, if that makes sense. My irrational self wants it, but my rational self says, “No, no you don’t.”
I can relate. That’s what I was trying to get at with pointing out how awesome the “Hulk, smash!” moment is in The Avengers before stopping to wonder who would actually be around to tell him to “smash” if it was a solo movie. I think that not having seen Bruce Banner since the first Avengers kind of hurt what Whedon did with him in Age of Ultron, but I like that The Avengers still has a character entirely unique to them, minus Edward Norton’s The Incredible Hulk and Ruffalo’s post-credits cameo in Iron Man 3. And since I don’t really know the Hulk that much from the comics I am left wondering if a dude who turns into a green monster when he gets mad is really worthy of another movie after striking out two times already in that department.
The Hulk comics (from the tiny bit I know about them) are usually more about the psychology and philosophy of the character than pure smashing when they’re at their best, and not in space. Therefore, they were never particularly popular in their early days, as they were not fun, and were (and still are) rather depressing. He’s a dark character when he’s at his best in solo adventures, and perhaps that’s just not a tone that fits into the MCU, as un-incredible as that might feel.
That’s what I’ve always heard, and regardless of your viewpoint on the effectiveness of Ang Lee’s panel approach to staging Hulk’s scenes that is a movie which very clearly tries to capture more the psychology and philosophy of the character than the smash-smash-smash. And that’s also a movie which did not make a lot of money.
Even as a mild fan of the character, I didn’t enjoy Ang Lee’s Hulk when it first came out, and I’ve yet to revisit it. All I remember is that it was dreary, and that the panels felt campy and out of place in an otherwise serious movie. But, that’s probably the best onscreen representation of the character, other than the TV series, which might be good, I have no idea. I’ve never watched it.
Definitely, because there’s much more to The Hulk than the MCU has let on, there’s red Hulk, Grey Hulk etc and different facets to the Hulk as he is, not even touching on Banner and as good a character as the traditional Hulk has been in the movies, he’s more than a mindless fighter. I don’t know if Marvel thinks its a bit too far for a talking, level headed Hulk but he should at least get another outing some time soon with Ruffalo.
Maybe this is the exact point where they say “no” because the market is already super-saturated with superhero movies… except I still want Scarlet Johansson to have her own movie…