Have now seen Black Swan, and it's utterly ludicrous. Maybe if you know nothing at all about dance, and you haven't any experience with movies about madness and obsession, e.g., The Piano Teacher and The Tenant (or even the Ellen Burstyn segments of Aronofsky's own Requiem), then BS might be impressive, but otherwise....
BS shares one of The Social Network's key problems: except for a striking opening sequence (which, in the light of recent controversy, Aronofsky has clarified is all Portman - well done Ms P.!), BS never really shows us what a top dancer or dance company does that's so very cool (Altman's overlooked The Company is vastly superior in this regard - somewhere out there Neve Campbell is firing darts at an image of Natalie Portman!). Indeed, the dancing is poorly photographed and tepid from what we see of it (although some painful-looking, en pointe close-ups are spectacular). We're told repeatedly that Nina wants to be 'perfect', but we have so little sense of her enjoying dancing or of her relishing gaining fluency and 'getting' new things in her performance, that that perfection feels completely abstract and contentless (not to mention literally risible at the end of the film). Compare with The Red Shoes (you knew this was coming): there we have a powerful sense of how Vicki Page's (Moira Shearer) madness flows not just from her svengali's cruelty but from the intoxicating, addictive powers of dancing and the stage themselves. And whereas the final fall in TRS is the kind of heart-stunning moment that no one ever forgets (and just is dance and death together), the final fall in BS is almost motionless, is clobbered by the plonking last line, and provokes distracting, practical impossibility thoughts: 'Huh? So she really had stabbed herself through? But then how was she able to dance Act 4?'
The scene of Nina clubbing with Lily could have helped flesh out Nina's relation to dance and this ideology of perfection she spouts. It could have been used to show us something about Nina's relation to her own body that maybe the rigidity of the rehearsal studio and her home life has stifled. Ideally we might see something on that dance floor that would make us think something like: 'Oh, so that's why that girl became/is a ballerina. Perfection would be if she can bring something of this out-of-control/out-of-ones-head/Dionysian dancing back to the studio...'. Unfortunately Aronofsky and his DP Libatique butcher the scene into a strobing nightmare so that we don't know who or hardly even what we're seeing. Opportunity squandered. [Update Sept 2011: someone has pulled out all the clubbing scene's subliminal imagery from the blu-ray of the film here. Wow, but it's hard to see the point if we can't see this stuff in real time (rather we just know that something funny is going on). And I stand by my view that Aronofsky and co. would have done better to make the clubbing scene explanatory of the perfection stuff (which needed explanation!) rather than use it to restate the insanity stuff (which didn't need to be restated, not even subliminally, given that we were repeatedly bashed right between the eyes with 'Nina's nuts'!]
Relatedly, the film's Balanchine-figure (a wasted Vincent Cassell) never does or says anything to show us what his talent consists in and why he might be a genius worth following unto death. We're told he's going to 'strip back' or rethink Swan Lake from the ground up, but everything we see after that looks pretty standard, and we certainly don't see any of the dancers protesting at or recoiling from any radical innovations, rather the basic vibe is 'Business as usual'. Indeed, as least as far as I noticed, the film never lets the audience in on the fact that fusing white swan/black swans = Odette/Odile roles is optional - that originally they were separate (a return to that could be our quasi-Balanchine's innovation: building on that, a separate Odile could hover/flicker onstage much of the time apart from the main choreography!). An opportunity is thereby missed to use the director/choreographer's refusal to even consider splitting the roles, certainly if there's any evidence that a new lead dancer might be experiencing a breakdown, as evidence of his mania/demonicness. But perhaps the film doesn't mention this possibility because it would suggest a deflating resolution of the crisis in the film: if there's going to a big problem with fusion, split the roles, and let Lily dance Odile.
Needless to say, too, nobody gets to be prima ballerina at a Lincoln Center ballet company who's as tentative and generally freaked out as Nina is. At that level, if you make it, you've been on a soloist track from an early age. That track selects at every point for bravura/swagger as well as for basic talent/training/movement quality. The biggest (rising/risen) star in ballet right now is Natalia Osipova. Here she is still in school at age 17, soloing her heart out and blowing people away. This is just before she joins the corps of the Bolshoi, where she was immediately given some solo parts. It was 4 years of ever-increasing attention in that role that led to her being promoted to leading soloist in 2008, then finally becoming principal dancer for the Bolshoi in 2010. We're supposed to believe of Nina in BS that she jumps directly from being a relatively unheralded corps member/occasional soloist to being the face of the company in the leadiest lead role ever: fused Odette/Odile. Not gonna happen.
A final note: 'ludicrous' may be a little harsh on my part. Substantively, I agree with almost everything that David Edelstein says in his review of BS, especially this:
[Unlike Altman] Aronofsky isn’t remotely interested in celebrating the Dance. Black Swan is full of scary-looking emaciated women, their dark hair severely pulled back, twisting and cracking their limbs and toes—puppets of a tyrannical male deity. Even before Nina begins to unravel, the dances are shot by a camera that seems to be shuddering in horror.But Edelstein still ends up sounding softer overall than I do here. His tone is, I suppose, more likely the correct or appropriate one. So, some concessions: while I'm deeply dissatisfied with BS, a lot of people put a lot of work and love into it. It's not the sort of dreadful, slapped-together Hollywood nonsense that there's always a surfeit of at local cinemas. And it's impressive and even fabulous that a small, artsy film allegedly about dance is on track to make $300 million world-wide. See, I can make people happy: I'm the Magical Man from Happy-Land, in a gumdrop house on Lollipop Lane!
 The scene doesn't work as a deafening club alienation scene a la Lynn Ramsay's Morvern Callar either. This was the scene/point at which I gave up on BS, when I realized that it was never going to come close to the standards set by its obvious influences.
 Metacritic scores Edelstein's review as 100/100. That's bizarre!