I'm with thylings on this. Something tells me this is a Xion look-alike for no reason whatsoever.
Too bad it's confirmed that Vanitas looks like an existing character. I would've been tempted to bet it was a totally original one that we'd see again in a new game.
I thought of Xion because of the black eyebrow and strand of hair. Like a Xion look-alike with yellow eyes. :/
We'll see. Maybe Vanitas is a hermaphrodite. >.>