James Gunn Is Already Writing His Next Film as Superman: Man of Tomorrow Hits Major Post-Production Milestone

James Gunn is not the type of filmmaker to sit around waiting for things to happen. While the assembly cut of Superman: Man of Tomorrow is still being stitched together in the editing bay, the DC Studios co-CEO has already moved on to his next project — and he is not being shy about it.

When a fan asked Gunn on Threads whether he was ready to start writing his next film, the director’s response was immediate: “Already in it. I had to do something while I was waiting for the assembly!”

That single sentence tells you everything you need to know about how James Gunn operates. The man who reinvigorated the DC Universe with 2025’s Superman is already deep into the scripting phase of his next feature, even as the sequel to that film barrels toward its July 9, 2027 theatrical release.

The Assembly Cut Milestone

Gunn also confirmed on Threads that the assembly cut of Superman: Man of Tomorrow is officially complete. For those unfamiliar with post-production terminology, the assembly cut is the first full pass of the film — all the footage stitched together in script order, before visual effects, color grading, and the final score are layered in. It is the moment a film stops being a collection of scenes and starts being an actual movie.

The milestone is significant because it means the project is firmly on schedule. Filming wrapped in August after roughly 93 days of shooting, and the post-production machine has been humming along ever since. A completed assembly cut this far ahead of the release date is a strong signal that the July 2027 date is not just a placeholder — it is a real target.

What We Know About the Next Project

Here is where things get interesting — and deliberately vague. Gunn has not revealed the title, the plot, or even the franchise connection of his next film. He kept it entirely under wraps, offering no hints about whether it is a third Superman film, a new DCU entry, or something completely different.

Fans have been speculating wildly. The most popular theory is that Gunn is writing a third Superman film, with some suggesting Mongul — the classic DC Comics villain — as the antagonist for a follow-up to Man of Tomorrow. Gunn did not confirm or deny any of these guesses, which is exactly how he likes it.

What we do know is that the project exists, it is being written now, and it is moving forward while Man of Tomorrow is still in post-production. That is a level of productivity that would make most studio heads nervous, but for Gunn, it is simply business as usual.

The DCU Machine Keeps Running

Gunn’s announcement comes at a pivotal moment for DC Studios. The Paramount-Warner Bros. merger has reshaped the corporate landscape, but Gunn and co-CEO Peter Safran have been confirmed to remain at the helm of DC Studios throughout the transition. That continuity is crucial — it means the creative vision that launched with Superman in 2025 will not be derailed by boardroom politics.

The DCU under Gunn and Safran is building something that feels genuinely interconnected. Peacemaker bridged the gap between the old DCEU and the new DCU. Lanterns is bringing the cosmic side of the universe to the small screen. And Superman: Man of Tomorrow is set to deepen the mythology established in the 2025 film, with David Corenswet returning as the Man of Steel, Nicholas Hoult reprising his role as Lex Luthor, and Lars Eidinger joining the cast as the iconic villain Brainiac.

Against that backdrop, Gunn writing his next film is not just a personal productivity flex — it is a statement of intent. The DCU is not slowing down. It is accelerating.

Gunn’s Track Record of Writing and Directing

Before he became the architect of the DCU, James Gunn built his reputation as one of the most distinctive voices in genre filmmaking. He wrote and directed the Guardians of the Galaxy trilogy for Marvel, turning a team of obscure comic book characters into one of the most beloved franchises in the MCU. His blend of irreverent humor, emotional sincerity, and killer soundtracks became a signature that audiences instantly recognized.

He also wrote The Belko Experiment, directed Slither, and wrote the 2004 and 2010 versions of Dawn of the Dead. The man has been writing and directing for over two decades, and his range — from horror comedy to superhero epic — is part of what makes his next project so difficult to predict.

When Gunn says he is writing his next film, it could be a return to his indie roots. It could be a new IP. It could be the next chapter of the DCU. The not-knowing is part of the fun.

What This Means for the DCU Timeline

If Gunn is already writing his next film while Man of Tomorrow is in post-production, the timeline for the DCU’s upcoming slate is starting to come into focus. A film written in late 2026 could realistically begin production in 2027, potentially hitting theaters in 2028 or 2029.

That would mean the DCU is looking at a pace of roughly one major film per year — a cadence that Marvel Studios perfected in its heyday. Whether Gunn and Safran can sustain that output while also managing television projects like Lanterns and Peacemaker remains to be seen, but the early signs are promising.

The competition is not standing still either. Matt Reeves’ The Batman universe is expanding, and the broader superhero genre continues to evolve. Gunn’s ability to write and direct at this pace gives the DCU a significant advantage — it means the universe can grow and adapt in real-time, rather than being locked into a rigid multi-year plan.

The Fan Theories Are Already Flying

One of the most entertaining aspects of Gunn’s announcement is the fan speculation it has ignited. Social media has been buzzing with theories about what the next film could be. A third Superman film is the obvious guess, but there are plenty of other possibilities.

Could it be a Guardians of the Galaxy reunion set in the DCU? Could it be a completely original story disconnected from any existing franchise? Could it be a deep-cut DC property that most casual fans have never heard of? Gunn has never been afraid to take risks, and his next project could be his boldest swing yet.

Whatever it is, one thing is certain: James Gunn is not waiting for permission to make the films he wants to make. He is writing them now, on his own terms, while the rest of the industry is still catching up.

Looking Ahead

The next twelve months are going to be massive for the DCU. Superman: Man of Tomorrow arrives in July 2027, and Gunn’s next project will likely be announced well before that. The assembly cut milestone means the sequel is on track, and Gunn’s writing progress means the pipeline is full.

For fans of superhero cinema, this is an exciting time. The DCU under James Gunn and Peter Safran is building something that feels fresh, interconnected, and genuinely unpredictable. And if Gunn’s track record is any indication, the next announcement will be worth the wait.

Stay tuned. The DCU is just getting started.