Well, origins part 1 is on Waypoint. I couldn't find a youtube video, yet. Somebody will upload it eventually. Anyways:
Besides the fact that someone else is voicing cortana (wish they would've hired Jen Taylor, but whatever.) I thought it was ok. (I also seem to be an optimist cause every time I say its ok or good everyone else hates it.) I guess that this proves that there are no surviving Forerunner anywhere at all, and that Halos do kill the Flood itself and all sentient beings.