Dr. Jekyll/Mr. Hyde: Josh Dallas-His costar on "Once Upon a Time" Jennifer Morrison said in an interveiw back in November that he, herself and few other cast members can all sing. Besides I think he should play the anti-hero and break free from the pretty boy Prince Charming role.
Emma Carew: Emmy Rossum-I know there are a lot of Emmy haters on here but I for one love her and her voice especially in the "Phantom" movie. I think she should be in another musical.
Lucy Harris: Natalie Dormer-I read on her bio on IMDB.com that she sings mezzo-soprano and while it might be a classical voice I think she has great dramatic acting chops from what I saw of her as Anne Boylen on "The Tudors"
Hugh Jackman, Kate Shindle as Lucy and ... I have no idea for Emma at the moment... Perhaps Nicole Kidman? But then again, she does not really have that strong a singing voice.
"TO LOVE ANOTHER PERSON IS TO SEE THE FACE OF GOD"- LES MISERABLES---
"THERE'S A SPECIAL KIND OF PEOPLE KNOWN AS SHOW PEOPLE... WE'RE BORN EVERY NIGHT AT HALF HOUR CALL!"--- CURTAINS