Due to limited space for the puppeteers, for the scene where the car is full of The Muppets after picking them all up, Amy Adams and Jason Segel were asked to operate the Muppets on either side of them.
Shortly before the DVD release Courtney Love, the widow of Kurt Cobain, gave an interview in which she accused The Muppets of "raping Cobain's legacy" by covering Nirvana's song "Smells Like Teen Spirit" as a barbershop quartet and that the filmmakers never received her permission. Surviving Nirvana members Krist Novoselic and Dave Grohl (who also has a cameo in the film as Animool) both loved the rendition of their song but refused to say anything about Love's statements.
During an interview with Terry Gross on her National Public Radio program "Fresh Air," Jason Segel said that during filming, he observed the choreographer, Michael Rooney, giving instructions to the classic movie star Mickey Rooney (who had a cameo in the movie) and calling him "Dad." Segel went up to Michael and reprimanded him, saying "you can't just call any old man 'Dad,'" and Michael told Segel, "no, he's my actual Dad."
The filmmakers decided to use only old-style techniques for all the Muppet effects, such as remote control and battery operated puppets rather than computer animation in order to keep with the original style and charm of The Muppets.
The first theatrical Muppet film that Frank Oz wasn't involved with. Oz performed and voiced Miss Piggy, 'Fozzie Bear', Animal, Sam The Eagle, Marvin Suggs amongst other Muppets in all the TV shows and all the movies until 2000. Eric Jacobson has since taken over Oz's official The Muppet Show (1976) characters.
This is the first theatrical The Muppets movie since The Muppets Take Manhattan (1984) to include the voice of creator Jim Henson. Although Henson's characters are voiced in the film by other Muppeteers, his (uncredited) renditions can be heard in archive clips of The Muppet Show (1976), including Kermit's introduction and a snippet of the song "Mah Na Mah Na".
The scene of Fozzie's "fart shoes" caused a controversy among the Muppeteers, some of whom considered the humor too low brow for The Muppets. In the film, characters did not appreciate Fozzie's proposal.
Steve Whitmire's original signature character, Rizzo the Rat appears very briefly in the finale of the film. This is the smallest part the character has ever had since his first film appearance in The Great Muppet Caper (1981).
The day prior to the film's DVD release, The Muppets were awarded a star on the Hollywood Walk of Fame. It is located in front of the El Capitan Theater, which is owned by Disney and "plays" the Muppet Theater in the movie.
In the montage where the Muppets are retrieved from their current jobs, Scooter is shown in a Google reception area. At the time of release, this is indeed an actual office; it is the reception of Google's office in Zurich.
According to the full version of Tex Richman's rap, "Let's Talk About Me" (found in the soundtrack and the DVD extras), Richman hates The Muppets because at his tenth birthday party, everyone was watching The Muppet Show (1976) and laughing. Richman, unable to laugh, was then ridiculed by all his friends.
The Blu-ray release of the film is the first to use the "Disney Intermission" feature. Upon pausing the movie, rather than a freeze frame, viewers are presented with the famous Muppet Theater red curtains which offer a gateway to new Muppetational entertainment. A series of quick gags unfolds on the screen, different with each pausing of the film. The release's other bonus features are also shown from behind the curtain, often with new Intermission-only twists. The "Disney Intermission" feature can be turned off in the menus, reverting the Blu-ray to a standard freeze frame when paused.
Bret McKenzie wrote four original songs in the film: "Life's A Happy Song", "Me Party", "Let's Talk About Me" and the Oscar-winning "Man or Muppet"; two more, "Pictures in My Head" and "The Whistling Caruso", were written by other artists, but produced by McKenzie. All other songs in the film are from earlier Muppets projects (such as "Rainbow Connection") or from outside The Muppets' universe (like "Forget You", "Smells Like Teen Spirit" and "Mahna-Mahna").
HIDDEN MICKEY: At the end of the film as the camera tilts towards the sky showing the fireworks, three of the explosions are in the shape of Mickey Mouse's iconic head. This is likely due to The Muppets franchise being owned by Disney. The exterior location used for the Muppet Theatre is the El Capitan theater in Hollywood, which is operated by The Walt Disney Company; the Muppets' Hollywood Walk of Fame star is also in front of it. It is also next to Jimmy Kimmel Live! (2003)'s theatre - a show on ABC, owned by Disney.
Rashida Jones plays an executive for the CDE television network. CDE is "ABC" (American Broadcasting Company) if you move each letter up 2 letters in the alphabet. ABC is owned by The Walt Disney Company.
In the previous Muppet Holiday Special "It's a Very Merry Muppet Christmas", the plot also centered around the Muppets putting on a show in order to raise money to buy and save their Theatre from a villain (played by Joan Cusack). In said special, the theater is made Landmark saying that it cannot be demolished and no matter who owns it, it will always be "The Muppet Theatre." This leads to a major plot hole in this film, as if the Theater was granted landmark Status, Tex Richman could not demolish it.
In Spain the "Muppets" are known as "Teleñecos", but "The Walt Disney Company" requested to change "Teleñecos" to "Muppets" in the dubbing for assuring the merchandising. The also wanted to change Kermit's Spanish name Gustavo to the original, but that was kept.
The trivia items below may give away important plot points.
In an early draft, Tex Richman would be revealed at the end of the film to be Kermit the Frog disguised in a human suit, having made up Tex's plans with the intent of getting The Muppets back together. The idea was dropped, after it was thought that children would be confused seeing Kermit lie. Steve Whitmire even swore to have his name omitted from the credits if the plot point made it into the final film.
Jim Parsons (Human Walter) is the only actor whose cameo appearance was never announced or rumored. Parsons was asked to not publicly talk about his scene and agreed to, but the filmmakers confirmed his appearance in the film (while not specifically saying he was playing the human form of Walter the Muppet) after Parsons' role information appeared on the Internet Movie Database. He appeared with (human) star Jason Segel, thus teaming up the stars from two of CBS' sitcoms: How I Met Your Mother (2005) (Segel) and The Big Bang Theory (2007) (Parsons).