The trailer for the much-buzzed Sundance hit Blue Valentine, starring Michelle Williams and Ryan Gosling, has made its way online via Yahoo! and offers a small glimpse of clips framed by a scene in which Gosling serenades Williams with his ukulele while she tap dances along to the music. The film has been getting solid reviews and Williams’ name in particular has been tossed around for Oscar consideration.

Check out the trailer below:

In an odd turn of events, the film was also branded with an NC-17 rating today by the MPAA [Deadline]. Those that have seen the film (which has shown at Sundance, Toronto and Cannes) say that there is very little, if any, reason to give the film a harsh NC17 rating. Mike Fleming at Deadline speculates it has to do with a somewhat risque sex scene that hardly features any nudity but is psychologically provocative.

After viewing the trailer, which comes across somewhat sweet, it is even more puzzling that this film could have any NC-17 material tucked in it despite the storyline that the couple’s relationship goes sour. For those that have seen the documentary This Film Is Not Yet Rated, you will know that comparing the material to other films is a moot point but I find it hard to believe a scene depicting begrudging sex is any worse than the spousal rape in A History of Violence or some of the complex sex scenes between couples that have fallen out of love in myriad domestic drama films.

Whether the NC17 sticks or not, this is definitely the right time to release the trailer and play it up for all the publicity it is worth. Somewhere, Harvey Weinstein (who’s company is distributing the film) is sending a thank you letter to the MPAA.

Blue Valentine is directed by Derek Cianfrance and will hit theaters in limited release on December 31st 2010.

Is the MPAA insane or is there something lurking within the film that warrants this harsh rating?