Yeah, that was pretty crazy at the end. Are any of the characters from Forward Unto Dawn in the game? I don't have an 360 so I've only played the first two games, but despite that, I really like the Halo universe, and so far I've loved Forward Unto Dawn.
The impression I get is that the guy listening to Forward Unto Dawn's distress call in the first episode intro is the adult Laski. That kind of implies that he'll be in Halo 4.