Devs disable the HUD for their gameplay trailers all the time, it makes them more 'cinematic'. Unfortunately it does not always mean you can disable it in the final game as some devs like to force their game upon you. Thankfully the PC has ini files and cheat engine etc to combat this.
It does look good, the success of the Just Cause games gives me confidence but I just hope they do not use the post apocalyptic barren wasteland as an excuse to make the game world exactly that...empty, unimaginative and lacking in content. If they put some thought into the map design they could find a balance between wide open spaces with sand dunes for all the vehicular combat etc and denser areas with structures for the onfoot combat. Just Cause 2 has an awesome game world, its vast and has plenty of different places and different styles of landscape.
Just pray they dont screw it up as the old movies are classics and even the new movie looks good too.