ALL of the songs are in it, and some new music was written for the film. No new lyrics, just new like background music that is needed for like, scene transitions and stuff.
Rosario Dawson .... Mimi Marquez
Taye Diggs .... Benjamin "Benny" Coffin III
Wilson Jermaine Heredia .... Angel Schunard
Jesse L. Martin .... Thomas B. "Tom" Collins
Idina Menzel .... Maureen Johnson
Adam Pascal .... Roger Davis
Anthony Rapp .... Mark Cohen
Tracie Thoms .... Joanne Jefferson
The entire original broadway cast, with the exception of Rosario Dawson.
EDIT: In speaking with a friend from filming. There are like, maybe two songs which may not be in the movie. They WERE filmed, but because the writers had to add much more dialogue to the movie, rather then it being a straight forward opera, some songs just couldn't be worked in. Which kinda sucks. The two songs which may not appear are Contact, and On The Street.