Alas, we forget MOULIN ROUGE?
There were once (or still are, in some cases) plans for URINETOWN, INTO THE WOODS, WICKED, DREAMGIRLS (Miramax was going full speed with this one, then total stand still), SUNSET BLVD, HAIRSPRAY (still happening, but very slowly), and others.
Don't know what happened to INTO THE WOODS. There have been draft scripts for the film pop up on eBay. Lots of talk during the revival - then when the show closed, so did hopes of a movie.
THE PRODUCERS and PHANTOM OF THE OPERA are the only ones that are definite.
"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