I would caution against equating the model with the code. The model would need to be relatively complete before most (?) of the code would be. I would note that Wags has mentioned that the hydraulics system as seen some progress and has been included into the game (with the model). That kinda tells me that there is still some work to do - however I have no idea how many people are working on it or how far along all those other pieces are.
BTW: I think that you meant to post this in the other thread :-).