Hold on to those whips and chains, 50 Shades of Grey fans. Rumor has it that formal casting offers for the film adaptation of the best-selling novel will go out to the actors soon after Labor Day.

There has been plenty of speculation so far over who will be the male lead in the highly anticipated film. Names like Matt Bomer, Ian Somerhalder, and Henry Cavill have all been floated around, but so far they have only been rumors. Fifty Shades author E.L. James has certainly not given any indication about her preferences to the press.

"I know who her number one choice for Christian Grey is ... She is never going to get him. He has dark hair. Of course, that's what she wants ... Okay, I can say this: Think of the most obvious, fitting choice. It's right in front of your face. I can't say anything," said writer Bret Easton Ellis.

Ellis should know, after all, he was one of the final contenders to write the screenplay for the movie. Unfortunately, he absolutely refuses to say who James was pining after to play the role of Grey, so we are all left to speculate as to who that might be.

Obviously, it's a big name, otherwise James wouldn't have such a hard time locking the actor down. Christian Bale seems like an obvious possibility (I mean he even has the same first name as Grey), as do younger leading men in Hollywood like Shia Lebouf and Zac Efron. Then of course there's the uber-popular Ryan Gosling. Regardless, authors of movie adaptations rarely get to have much of a say in casting anyway, so it's fairly moot point.

As for the female lead of Anastasia Steele, well, that one is considerably more uncertain. There really is no real consensus for a fan favorite or just of who is likely to play the role. That is perhaps partly due to the fact that the majority of 50 Shades fans are women, and therefore much more interested in which Hollywood hunk will be ripping off his shirt during the movie.

That being said, there have been a few candidates for Ana Steele that have been floated about. Mila Kunis' name keeps on popping up, as do Dakota Johnson's and Amanda Seyfried's (who just starred in the raunchy biopic 'Lovelace'). Truthfully, however, we will all have to wait until after Labor Day to see what kind of cast the 50 Shades crew can whip together (see what I did there?).