If it is Reach, then it looks long destroyed, so what's the point of having a flashback to a desolate planet?
What's the damaged ship in the Halo: Reach trailer though? ;-)
A... Damaged ship? I know it's a longshot, but I think that an undamaged ship, once hit with plasma, becomes damaged.
The damaged ship isn't in half, anyway. The Chief is in half of the Dawn.
[Edited on 06.21.2009 3:44 PM PDT]