After so so so much talking and dealing between Fox and Microsoft, an agreement has been reached (5 million plus 10% gross), Halo the movie is gonna be hitting the big screen in the summer of 2007
Source: Variety (need subscription for full report apparently ):
Edit:Master Chief is gunning for the bigscreen in summer '07. Fox and Universal have closed their deal to make a movie based on Microsoft's hit vidgame "Halo," with plans for a tentpole in two years. Studios will pay the tech giant $5 million against 10% of the gross....
IMDB: http://www.imdb.com/title/tt0464037/ (so it's been confirmed, that means it really is coming out 2007....... hopefully)