Microsoft has updated their official GameStock site with info galore on all the games they are showing off (thanks Mulder). Although Flash is required, you can find new gameplay movies in AVI format from most of their featured games, including Halo (listed under Xbox games), Dungeon Siege, MechCommander 2 and more. The new Halo footage features some first-person action in addition to the third person view that had been previously shown.