Robert Downey Jr. would never do a role that's not one of the two principals. He's also the kind of actor that's booked over a year in advanced. There's no way whatsoever that he'll be involved in this.
I really wanted Marion Cotillard for Fantine, but they clearly went younger. Hathaway is a good actress, I'm just getting tired of her peppy somewhat artificial persona and ONE DAY was the embarrassment of her career (let's hope she doesn't try to go for a British accent on this movie). I doubt I could buy her as a sick prostitute, and yes I have seen (and was impressed by) RACHEL GETTING MARRIED.
"Some people can thrive and bloom living life in a living room, that's perfect for some people of one hundred and five. But I at least gotta try, when I think of all the sights that I gotta see, all the places I gotta play, all the things that I gotta be at"