I'm not a fan of horror movies and I think Natalie Portman is okay, I do like movies about ballet having been a ballet dancer for most of my youth. So, I'd really like to check this movie out. Also, it strikes my curiosity as to if there is going to be any correlation to Nassim Nicholas Taleb's The Black Swan. I doubt it by seeing the trailer but, then again The Black Swan was all about events that are hard to predict and the highly improbable, such are considered outliers.
Below are some film stills from the trailer.