The planned WICKED movie was not a musical. It was planned as a film based off of the novel, no music involved but the score.
Certain shows I can imagine being better on film than on stage. THE PRODUCERS musical, for one, I was envisioning on film throughout the play.
INTO THE WOODS works better on stage than on film, IMHO.
MAMMA MIA!, I think would be much better as a film than a theatrical show (although the show is nice on stage, the plot is much better suited for film).
PHANTOM looks like its headed for great success as a film.
HAIRSPRAY is a great example of how something works better on film than on stage. Don't get me wrong, I absolutely love the Broadway show and enjoyed it more than the film, but on film, it works better.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle