Momentum Pictures has the first picture of Rachel Hurd-Wood as Sybil Vane on their website...I'm doubtful that the brown haired girl in the picture (the picture on Momentum Pictures website) below hers is her...I'm guessing it could be Rebecca Hall.Anyhow I've always though Rachel Hurd-Wood would be great as Sybil Vane at least in terms of looks. She's both young and beautiful with the perfect naivety and vulnerability look about her.
The only other person I've seen as Sybil Vane was Angela Lansbury in the 1946 adaptation...which I did not particularly like. Neither did I like Angela Lansbury's potrayal of Sybil Vane. Even though she was in her early 20's she looks much too old and mature for the role. And she sang this song about a bird or something when Dorian first came to see her show...yeah horrible...wasn't she suppose to play a Shakespeare play? Wasn't she Juliet when Dorian first saw her. I hope we'll get to see that in this new adaptation.
Pic: [Source, Source]