I'm sure it's largely in part to the success of Tim Burton's Alice in Wonderland...and that fact that Hollywood seems to love racing to make similar movies. So I present to you the big screen Oz productions in the work. Which one would you see?
Oz The Great and Powerful (previously: Brick) - Tells the origin story of the Emerald City's wizard, Oscar Zoroaster Phadrig Isaac Norman Henkel Emmannuel Ambroise Diggs. This story about a circus magician who's balloon lands him in Oz where his magic tricks are viewed as powerful sorcery. This Disney project comes from Joe Roth the producer of Alice and Wonderland...so that should create an idea of what they're going for. The script is written by Mithcell Kapner, and newest rumors include Sam Mendes directing Robert Downey Jr. in the role. Disney is producing.
Oz: The Return to Emerald City- Scripted by Josh Olson (A History of Violence) and produced by Basil Iwanyk and his Thunder Road label (Clash of the Titans). The story is a dark retelling of the land of Oz with Dorothy's granddaughter returning to Oz to take on the evil and darkness that has entered the Emerald City. This film is said to be based at least in part by Todd McFarlane's Twisted Land of Oz. Warner Brother's is producing.
Oz [Temple Hill]- Darren Lempke (Shrek Forever After) has written an Oz remake under the Temple Hill film label that created Twilight. Speculation about whether this is an adaptation of the famous 1939 story or a look at other stories is uncertain. Warner Brother's New Line is producing.
The Wonderful Wizard of Oz - Why shouldn't the English get involved? John Boorman (Excalibur, Hope & Glory) is said to be in the early stages of production of a film who's title comes from the L. Frank Baum book that inspired the classic 1939 film. Currently this film has no announced cast.
Wicked - Since 2008 there's been discussions about Marc Platt (Wanted) directing a film version of the stage success Wicked written by Stephen Schwartz and Winnie Houston (based off the novel by Gregory Maguire). Who knows how this film schedule might be bumped up or bumped back due to the other competition. Universal is producing.
Sources: MTV Movie Blog: Return to Emerald, LA Times: Toto Recall, LA Times: A New Wizard, Cinematical: Sam Mendes/Downey Jr., Variety: Mark Platt