Well lets talk about the end of the HALO 4 trailer. At the very end a strange thing screams very quickly and if you look at it in slow motion guess what i looks like A PRECURSOR! if you read HALO CRYPTUM bornstellor or the DIDACT cant remember witch one describes a PRECURSOR. And that is exactly what the thing at the end of the halo 4 trailer looks like read the book look at the trailer and see for your self.
PS. ITS THE CONCEPT ART TRAILER!