UPDATED 8/4/13 8:30 PM EST
I love the Muppets and I've been watching the Muppet Show lately. And I have always believed that Jim Henson was a creative revolutionary, a genius entertainer. I am surprised there hasn't yet been a biography tv movie yet on Jim Henson. But I forsee a movie of course. There is plenty to tell, how Henson got his start on a local show Sam and Friends, then various stints and commercials and specials and how he struggled to get the Muppet Show on the air but no network wanted it. At the end, he got a company in the UK to do it. His rise to success with various movies and then his 'mysterious' illness, his marriage and children. I think it was a straight off drama but didn't take it too seriously and brought comedy from its light and dark moments. One thing would be the voices of the Muppets, they would have to get the rights and the support of the Henson family.
I love the Muppets and I've been watching the Muppet Show lately. And I have always believed that Jim Henson was a creative revolutionary, a genius entertainer. I am surprised there hasn't yet been a biography tv movie yet on Jim Henson. But I forsee a movie of course. There is plenty to tell, how Henson got his start on a local show Sam and Friends, then various stints and commercials and specials and how he struggled to get the Muppet Show on the air but no network wanted it. At the end, he got a company in the UK to do it. His rise to success with various movies and then his 'mysterious' illness, his marriage and children. I think it was a straight off drama but didn't take it too seriously and brought comedy from its light and dark moments. One thing would be the voices of the Muppets, they would have to get the rights and the support of the Henson family.
Paul Rudd as Jim Henson
Not only the creator, director, writer of many Muppet projects but also the voice of many characters other than Kermit including Rowlf, Doctor Teeth, Link Heartthrob, Waldorf, Ernie, the Swedish Chef and much more. He not only did Muppets and Sesame Street but also responsible for Dark Crystal, Labyrinth and the puppetry in the first Teenage Mutant Ninja Turtles film. Jim was a striking man, especially when he had short hair. Paul Rudd (This is Forty, 40-year-old Virgin, Clueless and Knocked Up) is also a striking man, he can handle drama and comedy and a dramedy would be perfect for Henson.
David Cross as Frank Oz
Frank Oz was Henson's right hand man, now an acclaimed director. Frank originated Miss Piggy, Fozzie, Grover, Animal, Cookie Monster, Sam the Eagle, Bert, Yoda, and various others. He had a special relationship with Henson. He and Henson co-directed Dark Crystal. David Cross usually does comedy, he did some drama and he is the one that looks the most identical than the others I picked. Other people think they look alike especially when David Cross plays Tobias Funke in Arrested Development.
Will Forte as Jerry Nelson
Jerry Nelson first worked with Jim Henson in 1965 when Frank Oz got drafted and Henson needed somebody to perform the right hand of Rowlf on The Jimmy Dean Show. He has a distinct voice. Although he was uncredited, Nelson reprised his role as announcer during The Muppet Telethon in 2011's The Muppets. He died August 23, 2012 after years of health issues complicated by COPD. He voiced the Count, Floyd Pepper, Robin the frog (Kermit's nephew), Lew Zealand, and Gobo Fraggle. Will Forte (Saturday Night Live, MacGruber, 30 Rock, and Beerfest) can do plenty voices. Other than resembling him, I think they have a similar sense of humor. Also Forte had experience on a Variety Show which is what the Muppet Show was.
Simon Helberg as Richard Hunt
After high school graduation and a four-month stint of doing weather
reports at a local radio station, Hunt had his first inkling that he
might join the Muppets. His first project was The Great Santa Claus Switch in 1970, along with Fran Brill. A few weeks later, he was invited to be in a workshop production. The newcomer was so good, Henson asked him to work a Muppet appearance on The Ed Sullivan Show. He performed and voiced Scooter, Beeker, Janice and Sweetums. Simon Helberg (MADtv, 'Big Bang Theory') has done a spot-on Kermit impression and he's young and I am sure can bring the young spirit Richard had. Richard died from complications of AIDS in 1992, shortly after Henson.
Zach Galifianakis as Dave Goelz
The mechanically-minded Goelz worked for such
companies as John Deere, American Airlines, and Hewlett Packard as industrial designer. He then went on to design and build muppets and quickly went to performing. He did Gonzo, Boober Fraggle, Bunsen Honeydew, and Zoot. Zach Galifianakis (The Hangover) is a natural fit, he envelops himself in his roles. Maybe its the beard. Lots of these guys have beards. Like Frank Oz, Dave Goelz is still alive.
Taylor Handley as Steve Whitmire
Steve was young too like Richard Hunt, he did Rizzo Rat and minor characters on the Muppet Show and went on to do Bean Bunny and Wembley Fraggle and ultimately Kermit the Frog. He took over in "The Muppets Celebrate Jim Henson." Maybe Taylor Handley (Zerophilla, "Hidden Palms," "The O.C.," and "Vegas") is too attractive but he is a terrific actor (he is recently in a Playstation commercial). Steve Whitmare, Dave Goelz and Frank Oz are the only major players that are still alive.
Kevin Hart as Kevin Clash
In the early '80s, he performed regularly, with Jim Martin, on Bob Keeshan's Wake Up with the Captain (Captain Kangaroo). In 1979, Muppet performers were performing in the Macy's Thanksgiving Day Parade, and extra puppeteers were needed for the Sesame Street float. Clash was brought in to perform Cookie Monster for the event. Clash worked with Henson in "The Jim Henson Hour." He has had controversy lately but he did have a documentary "Being Elmo." He has performed Elmo, Clifford, Leon, Hoots the Owl, Baby Sinclair of the Dinosaurs and others. Now Kevin Hart (Scary Movie 4, Superhero Movie) is no stranger to controversy in his comedy. Maybe he might have trepidation portraying Clash, but I think he'd be good. 
Gary Oldman as Caroll Spinney
Caroll Spinney portrayed Big Bird. In the 70's of course he had brown hair and now he is best known for having white hair. Gary Oldman (Harry Potter and the Prisoner of Azkaban, Batman Begins, Dark Knight Rises, The Fifth Element) can alternate. He is a brilliant actor. In 1955, Spinney headed to Las Vegas, Nevada, where he created the show Rascal Rabbit. In the 1960s, Spinney created two puppet cats, Picklepuss and Pop, who he performed in various venues, including stage shows and some Bozo broadcasts. In 1969, Spinney met Jim Henson at the Puppeteers' of America Festival in Salt Lake City, following an ambitious experimental presentation, which combined different live-puppetry techniques with film projections. I think Oldman would draw sympathy. 
Emma Stone as Louise Gold
She was the only British member of The Muppet Show performing team. She joined the Muppet Team in 1977, during the second season of The Muppet Show. Her most well known character on the show was young and aspiring pig Annie Sue. While on The Muppet Show, she frequently worked as assistant to Jim Henson when performing characters that would require more than one person. She and her character Annie Sue will be back in the upcoming Muppets Most Wanted. It might be a short role but I think Emma Stone (Superbad, Amazing Spider-Man, Easy A) can make it memorable.
Anne Hutchison as Jane Henson
She worked with Jim in Sam and Friends. She and Henson met in a puppetry course at the University of Maryland,
College Park, where they were both undergraduates. They were married
for 30 years. Jim and Jane Henson separated in 1986, but remained close until Jim's death in 1990. She died April 2, 2013. Anne Hutchison is Australian, she was in Cabin in the Woods and 'Power Rangers Jungle Fury.'
Freddie Highmore as Brian Henson
Brian Henson is the third child of Jim and Jane Henson. As a child, he made several cameo appearances in Sesame Street. As a teenager, Brian Henson worked at Sesame Place. During the 1980s, Henson wanted to make a name for himself and find work without his father's help. He performed Jack Pumpkinhead in Return to Oz, operated special effects in Santa Clause: The Movie, and was a principal performer for the Audrey II puppet in Little Shop of Horrors. He performed Hoggle in Labriynth. I think Freddie (Charlie and the Chocolate Factory, Finding Neverland, "Bates Hotel") would make a good young Brian. Even though his younger brother John has performed Sweetums, Brian is a more hands-on Muppet performer.
I don't seem to be the only one to have this idea:
