well you dont beat safina,hantuchova and zvonareva back to back if you're not a very good quality player.
She already won a finale against a williams(tokyo 2007 against venus), it will be tough but she proved this week that she can play amazingly well.
and I just checked her h2h : she never faced Serena despite both being on tour for years now.
I just hope she'll play well.A win would be a great story but the sisters have been playing quite well so it'll be tough.
I'd say it is pretty unlikely Virginie will win, but I'm pretty optimistic that at least she is experienced enough, and smart enough and good enough to be able to make a real match of it. It will at least be a hell of a lot better than it would have been had Kanepi been the opponent.