http://halo.bungie.org/news.html?item=34632

So in August 2009, rumors circulated that Steven Spielberg was interested in making a Halo movie. Nothing ever came of them. A year later, though, in October 2010, they resurfaced. Still nothing. Today, Halo.Fr posted some scans (thanks, Sirkan) of the material that came inside the French press kit for Halo: Cryptum - and right there, in black and white (and French), is a paragraph that translates to

A film adaptation is set in 2012. It will be conducted jointly by two heavyweights of American cinema: Steven Spielberg and Dreamworks.

343 has been contacted for comment, but we've heard nothing so far. Seems like it might be a misunderstanding... or maybe just a well-kept secret, broken by the French.

If this is correct its great news however there has been so much talk both officially and unofficially about the films existence and direction that its very hard to believe anything until shooting actually starts. The film has been in flux for far to long and the rumor mill churning out so many stories. I'll believe its actually coming once Spielberg starts shooting, in fact even him saying he was hired to make the film wouldn't be enough to convince me it is actually coming. In Hollywood so many films get announced that never see the light of day or take years upon years to be completed. Spielberg himself confirmed Jurassic Park 4 years ago but even now the film remains in early stages and hasn't even started filming according to Universal!

So until the Halo film begins shooting I will remain skeptical, I know inevitably it will come but to believe anything as concrete before filming starts would be naive!

WTF is Halo: Cryptum??

It's a Halo book of the "Forerunner Saga/Trilogy" that details the events 100,000 years ago with the Forerunners. How they grew, fell, fought other species (even humans actually), etc.

Steven Spielberg is Dreamworks, he helped found it, not really a collaboration in that sense.

never trust the french....

I'm not getting my hopes up. I've waited far too long for that.

He was coming out with a Matt Helm movie too...

the only person I see playing Master Chief is Kurt Russell...but most likely
they'll have Tom Cruise or Brad Pitt

If it is indeed based on Cryptum, then it's highly unlikely that master chief will be present in that movie. But other than that I remember reading an article that forementioned that if the movie was based around master chief, it would not be about him - he would be a side character as he had not enough substance or something.