Audrey Hepburn and Natalie Wood in "Black Swan" would be just plain fantastic. Garland AND Crawford would be a bit too much star-power added, but I'd DEFINITELY want to watch.
Anyway since I hate remakes, I'd go for a gender switch reworking (in the present? golden age of studio era instead of silents? not sure) of "Sunset Boulevard" with Christopher Plummer as Norman Desmond and Natalie Portman as Joan Gillis.
Anthony Hopkins would play the butler Max with a big/secret crush on Norman and the Nancy Olson part can go to Paul Rudd (or whoever, not really important).