http://www.youtube.com/watch?v=00_EyaZpbsU
at 9:48
Could be a place holder but it would certainly imply the possibility of a Halo installation playing some sort of role in the story. The planet looks interesting too, especially considering it appears to be totally destroyed.
I remember Greg Bear’s books describing the destructive power of a Halo ring being used against some planets but this seems to go beyond that. Anyone want to speculate?