In another article I argue that the reboots we're seeing so often in movies are a good thing. Our cultural willingness to explore and re-explore our favourite stories points to those particular stories serving the same function as the myths of ancient Greece or Rome.
One story I don't mention, but which certainly qualifies in this category is The Wizard of Oz. We're not seeing it rebooted so much as seeing people spin variations on it. Many many many of them, with no sign that we're getting tired of it.
Indeed, this was already the case when the movie debuted in 1939. It begins with a title screen, saying:
For nearly forty years this story has given faithful service to the Young in Heart; and Time has been powerless to put its kindly philosophy out of fashion. To those of you who have been faithful to it in return… and to the Young in Heart --- we dedicate this picture.
It had already been made as a feature film at that point. In 1925, Oliver Hardy starred as the wizard, and there was much slapstick, and according to one commenter, not much faithfulness to the original novel.
The Judy Garland version actually flopped at the box office, initially. But resurgence from initial failure or indifference is a sure sign to me of a powerful cultural myth, and the story is still watched and referenced today (one of the characters in The Avengers refers to flying monkeys, and Captain America, reawakened after having been frozen in ice since WWII, remarks "I got that reference.")(the list of TV shows and movies that reference it goes on and on and on, if you'd care to have a look).
L Frank Baum (author of the original Oz novels, of which there were seventeen)'s imdb page lists a whopping 125 credits, almost all of them Oz related. They include:
The Wiz - broadway musical, turned film, with an African-American cast - Diana Ross as Dorothy, 
Michael Jackson as the Scarecrow, Richard Pryor as the Wizard.
Two Russian TV movie versions, twenty years apart, both called "Volshebnik izumrudnogo gored" in which the evil witch Gingemma conjures a cyclone that whisks little Elli and her dog Totoshka (who apparently can speak, and suggests that Elli take the witch's silver shoes) as she traverses the Magic Land to find the wizard Goodwin, along with her companions Strasheela the Scarecrow, the Cowardly Lion and Zhyelyeenee Drovosyek the Rust Iron Wood Chopper, all the while being harrassed by the witch Bastinda, who sends flying monkeys, an ogre and knife wielding tigers.
A Japanese version: "Ozu no mahotsukai"
Thanksgiving in the land of Oz
Return to Oz - a movie I remember from 1985, which made a friend of the family's youngest child run crying from the room when the disembodied heads of the witch woke up and starting calling out "Dorothy Gale! Dorothy Gale!!" as she attempted to steal a box of life powder.
The Muppets Wizard of Oz
Tin Man - a mini series, with Richard Dreyfuss and Zooey Deschanel.
And I remember being particularly fond of a Wizard of Oz episode of Fame.
Sam Raimi's movie of Oz the Great and Powerful will hit the big screen soon, starring James Franco as the wizard, the story exploring his initial entry into the land of Oz. Other cast members include Michelle Williams, Rachel Weisz, Mila Kunis and Zach Braff. Its budget is estimated at $200 million. This is clearly expected to be a major release.
Wicked - the musical based on Gregory Maguire's 1995 novel, retelling the story from the Wicked Witch of the West's point of view (Maguire has gone on to write three other books from the points of view of other Oz characters), currently holds box office records for highest weekly gross in 
London and Broadway. The long running London production won the Olivier Award for most popular West End show in 2010.
Margaret Atwood wrote an essay about the novel and the movie, collected in her book Moving Targets: Writing with Intent.
Salman Rushdie lists the movie as his first literary influence, having written first story at age ten, titled "Over the Rainbow." He wrote an essay about the movie which has been published as The Wizard of Oz, and is collected in his book Step Across This Line: Collected Non-fiction 1992 - 2002.
The movie and its characters have been completely embraced by the LGBT community, the term "friend of Dorothy" meaning a gay man.
Mark Kurlansky opens his book The Last Fish Tale, a non-fiction look at the history of the fishing industry in and around Gloucester, MA, with a description of the annual greasy pole run, in which very macho blue collar men try to run to the end of a phenomenally slippery pole suspended over the ocean as part of a yearly festival. The participants are usually drunk, and costumed, quite often, as Dorothy.
And many a cloud of pungent green smoke has wafted up in living rooms, basements, and midnight screenings in alternative movie theatres, as the movie is played simultaneously with Dark Side of the Moon.
I predict the variations on this story will continue. Some will be inspired, some insipid, and some completely bizarre and unexpected.
