Due to the extensive wear and damage to his armour it is safe to say that his shields aren't working. Most people don't realise that over time sand does extensive damage to metal. This could also suggest that he has been there for a little while. As for the Forerunner Machine, it seems to be some sort of Contender Class AI (possibly Medicant Bias). It would be protecting something very important. Edit: It could obviously just be camouflage but I like looking to all possibilities before I rule something out. He also looks smaller in the trailer and hunched over, like a broken soldier. What do you think? Do you think I'm right? http://www.bungie.net/7_Halo---John39s-Cloak-Theory-2/en-us/Forum/Post?id=60699863#referred-Gaming In my new theory I believe that he is also not wearing most of his armour. For some reason this one is much more popular though and I think that my full theory should be fully heard rather than just parts.