I think that any musical, under the right direction and with the appropriate writing (re-writing), will work. The best example I can throw out there is "Chicago". The *movie* is a movie of the musical... not the musical filmed as a movie, does that make sense. When I first heard they were making a movie of "Chicago" I didn't think they could pull it off. But I love it. And it's VERY different from the play.
I think with Wicked... they could even revisit the book and explain some things that are left out of the stage production.
Happy, smile! Sad, frown! Use the corresponding face with the corresponding emotion! - Kate (Meg Ryan), French Kiss