did Natalie Portman do her own dancing in ‘Black Swan’?

Natalie Portman won an Academy Award for her work as a ballet dancer in Black Swan, but some are saying she was a little too good, that there's no way she could perfect moves in months that real dancers can't do in years.  Her fiance Benjamin Millepied, who was also the choreographer for the movie, says that's 15 percent nonsense.  

"It was so believable, it was fantastic, that beautiful movement quality," he told the LA Times. "There are articles now talking about her dance double that are making it sound like [Sarah Lane, her body double] did a lot of the work, but really, she just did the footwork, and the fouettés, and one diagonal [phrase] in the studio. Honestly, 85% of that movie is Natalie."

And the Huffington Post speaks to another dancer who worked on the movie who says essentially the same thing.  That it was mostly Natalie and she was really good.  The real question is who cares.  I assumed it wasn't Natalie. That shit looks hard but I don't care either way. It's a movie. If I wanted to see literal reality I would just sit here and stare out the window.