The Project Zeus orbital weapon depicted in the movie is based on a real concept and it is theoretically possible. United States Air Forces's Project Thor, nicknamed Rods from God, it is based on the principle of Kinetic Bombardment: tungsten rods are dropped from a satellite in orbit and, depending on its size, could destroy from deep bunkers to whole cities.
To prepare for his role as Firefly, Ray Stevenson read the G.I. Joe comics. He became a fan of his character, even putting in his own money so that the costume designers would make a mask to go with the costume.
The vehicle driven by Roadblock in the final action sequence is a relatively new U.S. Military vehicle called the Ripsaw. As of 2013, it is deployed in a display capacity for the U.S. Army. It can reach top speeds of above eighty miles per hour, and an amphibious version is in the works.
Jinx is seen training with Snake-Eyes dressed in a red outfit, as in her original appearance in G.I. Joe: The Movie (1987). Later on the mountain she is seen in her black and yellow ninja suit from G.I. Joe: Sigma 6 (2005).
In the G.I. Joe (1985) cartoon, Flint and Lady Jaye had a bit of a romantic relationship with each other. In the comic book series, they are an actual couple. This relationship is foreshadowed following Lady Jaye's visit to the Presidential party.
According to Robert Remus (Sergeant Slaughter), he was originally supposed to appear in this film, but he was unable to do so because of right's issues with Hasbro and Mattel. Joe Colton was brought into the script to replace him.
The battle on the Himalayas was shot in a New Orleans warehouse previously used to build NASA rockets, that had been fitted with a green screen wall at a very steep angle with a lot of rigging above to swing the stunt people through.
Apparently this is the final film that Channing Tatum and his stunt double Mark Foran worked together. The two remain friends but Foran is pursuing an acting career of his own. He appears in Angelina Jolie's new movie Unbroken (2014).
Arnold Vosloo: His face is only seen for roughly three seconds (not counting the few times you see his photo on a computer). The rest of the time his character is played by Jonathan Pryce as Vosloo's Zartan is impersonating The President via the nanotechnological disguise.
The trivia items below may give away important plot points.
In the final fight between Zartan/President and Storm Shadow, a metal case in the background bears the logo of the Umbrella Corporation, the villainous organization from the Resident Evil series of video games/cartoons/movies.
Duke is killed while trying to save Flint, a fellow Joe soldier. This a homage to G.I. Joe: The Movie (1987), where Duke was cut down trying to save a fellow Joe (in this case his brother Falcon, and he survived).
The world's eight nuclear nations meet at a summit held at Fort Sumter. The events of the summit vaguely mirror the famous American Civil War battle at Fort Sumter, in which nobody from either side of the conflict suffered any losses (save for one malfunctioning weapon that resulted in the death of a Union soldier) in that even though all eight nations launch their nuclear arsenal, nobody is killed by nuclear weapons in the end.
When Roadblock, Flint, and Lady Jaye first enter the recreation center where they hide out, "Abernathy's Gym" is visibly painted on the wall. The full name of General Hawk, commander of the G.I. Joe team (who is played by Dennis Quaid in G.I. Joe: The Rise of Cobra (2009), but does not appear in this film), is Clayton M. Abernathy.
The movie's intended release of June 2012 was changed to March 2013, which led to widespread speculation that the studio had ordered re-shoots. As Channing Tatum had become an A-list star following the success of 21 Jump Street (2012) and Magic Mike (2012), it was believed that the studio wanted to take advantage of his popularity by re-shooting his character's death scene in the first act, and giving him a more prominent role in the rest of the film. This rumor turned out to be false (the delay was already announced before 'Magic Mike' was even released); the postponement of the movie was simply to avoid releasing it in the same month as 'Mike', and to convert the movie to 3D in post-production.