I think it was time for a Halo movie a couple of years ago. The games have been steadily getting more and more unpopular and what with Bungie supposedly stopping after Reach (last I heard, I might be wrong), they are running out of time. If they can't release a film before or shortly after the release of Reach then it will likely be past the time anyone cared. Unfortunately if they do attempt to make it in that time it'll probably be rushed and turn out terrible (that is assuming it was going to be good if not rushed, but I don't want to get people started on that). Probably their best bet is to wait and see if Bungie makes another trilogy and then make it. That would also give them time to sort out who in the movie business cares enough to make it.
Personally, I'm curious enough to want to see a Halo movie (and I liked the idea of someone from District 9 working on it, as someone mentioned, I saw that over the weekend, it was pretty good), however I really hope they decide not to show Chief's face, not because of any belief that it will ruin the series, but because I'm certain that so many fans of the series will have formed a mental picture of what he looks like that as soon as they show his face 90% of the audience will be outraged that he looks nothing like they imagined. I would have to avoid the internet for a decade just to keep away from all the whining, and then I know I'd still pass people in the street complaining about it. Anyway I almost never think of him as having a face, I just see the helmet, which is probably for the best.
