what me worry? this guy made: wing commander, starlancer, & freelancer! consider these r&d for SC... freelancer hints at much more depth that was incomplete due to publisher intervention, which is gone with SC. hopefully Roberts will not become a George Lucas.
they are using cryengine3, as he pointed our in the last video they have crysis 3 functionality right out of the box. i believe the last video he alluded to the art assets being the largest amount of work facing them prior to the ks.
so i imagine most the design is done (what was left out of freelancer along with what has been dreamed up in the last 10 years), the engine is done and is a proven platform for FPS with vehicles.