Went to see this last night and rather enjoyed it, however I do think Hugh Jackman and Russell Crowe were miscast, they are both decent enough actors, however they really can't sing (saying that Russell did get better as the film went on) just get the feeling that they wanted A List Actors to try and draw people in.
Ann Hathaway and Amanda Seyfried were amazing, fantastic acted and sang beautifully, they did kind of carry Hugh & Russell though in my opinion.
Oh I can assure you Hugh CAN sing. Check him out on You Tube. This wasn't his best vocals, but down to using "live vocal takes" so a few of those umpteen takes were probably much better than the one Hooper went with. But he wasn't miscast, nor, the more I watch it and vocal quality a la stage version becomes less and less of an issue, was Russell. I agree with the poster up thread (I think it was Irma Bunt
who said they'd seen and heard Javroche sung better but never better acted.