OK, Heathen, I saw Chief, but no Cortana.
Also, what the hell is up with that one chick Spartan we see taking off her helmet/pointing a pistol at the girl in the stroller/wheelchair-thingy in the rose garden? I paused right there, and all I see is what looks like a scene from the Pokemon universe's version of Cops.

Also, other things I've noticed:
THE HELL IS UP WITH THE SAMURAI ELITE ARMOR?
MC/Arby duel scene: Fucking awesome looking.
Why is MC riding a robot armed with what looks like a Warthog chaingun and emblazoned with the number "117" through space and into a Covenant ship hangar? WHY?