After the news that the adaptation had found its director, a release date for North America has been set. The theatrical release will start August 1st, 2014.
Sam Taylor-Johnson is directing the film.
Guardians of The Galaxy will also open on that date. They don't target similar audiences that much, so Fifty Shades shouldn't come as any competition to Guardians.
The film is rumored to be NC-17, but I bet Focus Features would be much happier with an R rating.