Logged by Konrad in #hbo on irc.bungie.org after the commercial aired.

Konrad: Frankie, is the so-called Shield Grenade a game element?

Frankie: Nothing in the trailer was placed there by the agency - that is to say, every object and action was put in there with Bungie's consent and usually assets.

Frankie: Which you have t assume we wouldn't do without good reason, riht?

Two children, a boy and a girl, are lying in a clearing amongst blades of grass, staring up at the night sky.

Boy: You ever wonder what's up there?

Girl: Like what?

Boy: Maybe someone up there is wondering what it's like here.

Girl: I guess. Do you think we'll ever meet them?

Boy: I hope so. Don't you?

We see the Master Chief's helmet now in same clearing where the two children were a moment before. Screams, noises of combat and what sounds like incoming artillery fire can be heard.