Ok, now i know that thier have been a lot of posts regarding the Halo Movie.
Now i just want to write down what i know so far and have yall correct me or update me if what i put is wrong/old.
*Ok so the most recent news i have heard of is that Steven Spielberg is making the Halo movie.
*The movie will be based off Halo:Fall of Reach book completley, following Jon 117 and the rest of Red team from when they were abducted at age 6, through training, and fighting the covenant.
*It will be released in June/July 2012
Please correct/update me if possible
I’m pretty sure no one is making it, way too much money and no one really wants to.
I heard someone was but then pulled out.
Taken from Wikipedia article: Halo (series)
“At one point, filmmaker Steven Spielberg had expressed interest in being involved in the making of a film adaptation of Halo.”
It is currently in Standby last I heard… at this point I think it would be better if Microsoft just funded the entire thing, or if 343 Made it within a Game Engine as a 2 hour long cutscene-Then filesave as .avi/.mov. 
True about the money
But
Steven speilberg officially said that he had ALOT of Interest in a halo movie, especcialy a script written by i forgot who following Halo:Fall of Reach book and he loved it!
PLUS Frankie said a halo movie WILL HAPPEN
All I heard is that yea hes making it. Technically there is a Halo movie already, Bollywood made a Halo Musical. 