That sucks that there's no Legendary ending. You know what would have been an awesome way to do bonus cinematics? A Legendary ending that compounded based on what other Halo games your profile completed on Legendary.

If you beat Halo 1, you'd get to see an extended scene where the Pillar of Autumn takes off. Then, if you beat Halo 2, you'd get to see a scene aboard The Arbiter's ship, where they begin their pursuit. After that, if you'd beaten ODST, you'd get to see a scene starring Buck getting off the planet. Then the Legendary ending for Reach, and finally, if you'd beaten Halo 3, a scene pertaining to the ultimate fate of the Chief.

It's supposed to be the last Halo game from Bungie, right? That would have been an excellent way to end things.