The most influential (though perhaps the most muddying to the canon) is the 1939 movie musical, a loving tribute that nonetheless made several departures from the book, and which has so firmly entered the pop-culture imagination that it's often a surprise for first-time readers how their hive memory differs from the original stories of Oz.
And that's important. The relationship between a work and the audience is fluid, and sometimes an adaptation can differ wildly from the source material and still be true to the spirit of the original (Clueless is still the most artistically and satirically successful version of Emma). However, the reverse isn't the case; an adaptation that hat-tips a hundred particulars and loses the spirit of the work is, at least on some level, falling short. (Nearly every Alice in Wonderland adaptation dispenses with the vital anger and frustration that so sharply characterizes the Alice of the books.)
Which brings us to Oz: The Great and Powerful. It attempts to tackle this backstory and present a new vision of Oz. Great, sure! However, tackling this particular story of a man in power with any faithfulness to the canon requires framing the women around him as characters of agency and determination, some of whose power he's quite literally stolen for himself - his deception, not his ability, is what builds his legend, and his rule is fated to be a blip in a history of women who wield the power to which he pretends.
Let's see how they're doing:
“…When Oscar Diggs (James Franco), a small-time circus magician with dubious ethics, is hurled away from dusty Kansas to the vibrant Land of Oz, he thinks he’s hit the jackpot—fame and fortune are his for the taking—that is until he meets three witches, Theodora (Mila Kunis), Evanora (Rachel Weisz) and Glinda (Michelle Williams), who are not convinced he is the great wizard everyone’s been expecting. Reluctantly drawn into the epic problems facing the Land of Oz and its inhabitants, Oscar must find out who is good and who is evil before it is too late. Putting his magical arts to use through illusion, ingenuity—and even a bit of wizardry—Oscar transforms himself not only into the great and powerful Wizard of Oz but into a better man as well.
Well! It's certainly an interesting attempt to make a hero out of a dude who's a pretty thorough dickhead for much of his tenure in Oz and only becomes good after he gives up power and starts learning from women! But maybe the actual movie promises more.
Huh. Okay. Some things!
1) Trailer, you really did not even have to tell me this is from the same people who did Alice in Wonderland. Trust me. We know.
2) Wow, every line in that entire thing made a little *thud* as it landed, didn't it?
3) Rachel Weisz and Michelle Wiliams are automatically better than this movie. Mila Kunis has presence and really solid comic timing, but is not generally cut out for gravitas (making her a member of the Elizabeth Banks Squad). James Franco should just sit down somewhere for a few years. None of this bodes well.
4) Man, this really is a pitch for a movie about a bunch of powerful women who desperately needed a dude to save them, isn't it?
Which is strange, because the Oz books are stories of women. The catalyst is Dorothy Gale, the brave and practical girl from Kansas who accidentally arrives in Oz in the first novel. In her quest to return home, she defeats the Wicked Witch of the West; she's aided by the powerful Good Witch, Glinda. In later books, Ozma, the rightful ruler of Oz, reappears, and her adventures with Dorothy and Glinda against the evil witch Mombi and some sketchy princesses form the plots of several books in the series. In later books, other girls join the lineup of protagonists, including Scraps the Patchwork Girl and stalwart Earthlings Betsy Bobbin and Trot. Ladies are pretty thick on the ground in Oz.
The Wizard of Oz appears in the first book as the self-proclaimed ruler of Oz; however, Dorothy discovers he's a charlatan, and a large part of restoring the balance of Oz is his abdication. He reappears in later books, with a backstory that was adjusted according to audience response - originally, part of his rise to power in Oz was to hand over baby Ozma to Mombi, something omitted from later books because readers didn't want to think of the sideshow magician as a ruthless usurper. (He eventually got a happy ending, with a home in Oz and a dispensation from Ozma to study magic under Glinda - whose power, it's made clear, will always exceed his own.)
It is, of course, possible that this trailer is misleading! (That happens. The Dredd trailer was such a mess it tanked a really dark and thought-provoking movie.) Perhaps Oz: The Great and Powerful will turn out to be a searing exploration of what happens when a powerless man discovers power, and the lengths he'll go to in order to seize the throne under pretense of ability and right, and what happens to the women in power when someone attempts to marginalize them and they have to fight back! I hope so - that movie sounds boss-ass! Is it more likely we're looking at kind of a mess? Probably.
I am no purist for Oz; I tend to enjoy adaptations that examine and critique it more than the source material. However, it's pretty hard to be enthusiastic about - or even to ignore - that this movie is marketing itself as The Man from Oz, featuring the Ozettes (that poster, seriously), and invites us to go to the movie to enjoy the sidelined women of Oz.