As far as I know, we just have confirmation that everything shown is "in-engine," which is still true for GT5's photo travel mode. I think it's reasonable to think expectations will be more down to earth when we see actual gameplay -- it's not like this isn't common practice for lots of high profile games.There are other stuff in GT5 photo mode to utilize quality of visuals beside dof. It has much better shaders and lighting, plus shadows are not last gen like in actual gameplay. What H4 gifs are showing is exactly how game looks like with DOF which I guess will be there in game too just not in your face while you are shooting.
Keep in mind that this was a 'screenshot' for Halo 3:
http://www.bungie.net/images/games/halo3/screenshots/H3_MasterChief.jpg
Compared to this now:
http://i.minus.com/iflymF8cHm42X.jpg
This seems like fairly common practice for high profile games, and not just on 360.