Of course He'll Be Back...
An Arnold fan site recently got this quote from the man himself:
In fact, I'm very happy that the studios want me to be in Terminator 5 and to star AS the Terminator, which we start shooting in January and I'm also going to do King Conan - to play that role and also to do another Twins movie. So I feel very proud of that. I feel very happy and I'm looking forward to doing those films.
My initial reaction was that this was silly. How can they keep casting an obviously aging man as part of Cyberdyne Series 101, which is presumably an assembly line of cyborgs?
Then I thought some more, and it actually totally makes sense. Bear with me.
I'm afraid we're going to have to assume that all Terminator movies are canon. I know you don't like to, but there's no indication anywhere that they should not be. So, proceeding with that in mind - it makes sense that the look of an endoskeleton would never change. But Terminators are covered with human flesh and blood. Human skin ages, and would do so much faster without internal organs like lungs oxygenating them. Since the robots also don't eat, the organic cells would not be powered the natural way. And we know they don't have internal organs because Marcus Wright was unique in Salvation in that he had a human heart.
Well, you could say, maybe there's some kind of nanite swarm in there repairing the cells in a more complex way. Maybe - but then Salvation established that Skynet was kidnapping humans en masse to basically take their skins off and give to its robots for clothing. This means the organic tissue is a transplant rather than spontaneous generation, and I think it's this story element, rather than hilariously bad dubbing, that got the infamous "Sergeant Candy" scene cut from T3 - it would have established that T-800s use one template and all resemble Arnold at a single point in time...
So basically - yes, the organic shell on a T-800 would absolutely age. We could also - now that Sgt. Candy isn't canon by virtue of being a deleted scene - easily have Arnold play an older human character, but his actual words say he'll be the Terminator.
However, I live in California, and we all know better than to take Arnold at his word. If they must do this, would you rather see him be cyborg, or human? And who wins a fight between him and Christian Bale?
via Latino Review