Until I see an anouncement from bungie, MS, a movie studio or a official website I refuse to believe that there will be a halo movie.
As pointed out before, the nature of the game and hero is such that it would make a poor movie without hacking at the story and plot.
The closest that they could get without making a screw-up would be to have another character as the hero (maybe a marine) and only show up the MC on the odd occasion. This way they can develop a character, with a face, love interest and past without screwing up what bungie as made in the game.
I still think though, that a halo movie is a bad idea, in the long run. Some things just don't cross media boundries very well.
