I think they can take the existing material and make it darker in tone with only a few minor tweaks. For example, in the second act when the "townspeople" are hunting for Elphaba, they can open that up in a film and turn it into a real action scene, complete with torches and pitchforks, etc.
I just think the stage musical has been slowly slipping further and further into a tweener revue, mostly in the way it's acted. "Popular" has gotten so giggly now, it's almost psychotic. The two leads are played as junior high students rather than young college women struggling to find themselves and figure out who they are.
Hopefully, the right director (along with the right cast) will take the overblown cuteness out of it and return it to its origins.
I have high hopes for a film adaptation. Whenever that might be.
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22