The film-to-stage adaptation has become a category all its own in contemporary musical theater -- I think it might be smart to look at works like Hairspray or Singing in the Rain when we think about what a stage version of American in Paris might be.
It's representative of the shift of cultural power and influence from Broadway to movies. It used to be that Broadway musicals transferred to film with a great deal of pomp and fuss, as if doing the movies a favor, and now it's mostly the reverse, with the theater often relying on properties that were made for the movie house, and also on movie stars to sell tickets.
The limited success that Stiefel, Baryshnikov and a few others have had in movies is one thing. But movies aren't Broadway, where the performer is exposed for long periods of time and does not have access to the movie director's arsenal of tricks that allow him/her to stitch together "a performance" out of bits and pieces from many takes. Every performance on Broadway is the only "take" the audience gets to see.
Off topic, but Baryshnikov had a success in movies unparalleled by any other ballet star. He was a genuine movie star and he proved himself a pretty decent actor as well. He's been appearing on stage recently and without having seen him I'll bet he acquits himself well.
Stiefel hardly compares, but perhaps his timing was off. Baryshnikov came along at just the right time, with popular interest in ballet at a peak. (Also nobody was going to get any Oscar nominations for Center Stage.)
As for that "arsenal of director's tricks," they can only go so far. There was no magicking away the disaster that was Julie Kent in Dancers.......
I didn't really follow along with the critical commentary when Wheeldon made a version of AiP for NYCB -- I was glad to see that thread, but I do think it's a very different job to stage a musical adaptation of a film than it is to make a ballet based on themes from the play or the film. Wheeldon's suite of dances from Carousel has many virtues, but it is not a set of excerpts from a stage show.
Very true, but the NYCB piece does give us an idea of how Wheeldon initially conceived the music for dancing. It will be interesting to see if he uses some of the same choreographic material or tries something new with it. Quiggin's analogy with Robbins is on the mark, I think. Big shoes to fill. This is a very ambitious project for Wheeldon to take on, if he is indeed directing the production.