Spartan IVs Seen In Halo 4 Campaign?

While performing our review of the Microsoft E3 Briefing and going through our photographs, we noticed something interesting; what appears to be a second Spartan in the Halo 4 Trailer.

While the mystery character has an ODST style helmet, the character is also appearing to wear what appears to be some form of MJOLNIR armor standing behind the Master Chief.  Could this be an indication of Spartan-IVs in the new upcoming campaign adventure of the Master Chief as well as multiplayer?  We’ll keep digging, so stay tuned.  In the meantime, take a look at the photo below and tell us what you thing.