Sam Raimi and James Franco are working on a Wizard of Oz prequel, telling the story of the arrival of the wizard.
Everything I've seen about it so far looks intriguing, but I have to be honest: since reading Wicked and it's sequels, I've never been able to look at the Oz story the same way again.
Now that is a something I would love to see brought to the big screen—and not as a musical.