Microsoft has released the full trailer for the Forward Unto Dawn, the live action digital short that will accompany Halo 4. The trailer is fairly impressive as it shows a bunch of cadets going into training and almost feels a bit like Starship Troopers until Master Chief shows up at the end.
It's fairly good stuff and well put together. The only frustrating part of the thing is that it teases you as to what a live action Halo move could have been.