Wouldn't it be cool if they actually made a Terminator film showing the War, but when it was released on DVD it had an alternative ending? The alternative ending being the machines win (because obviously we know they don't).
I'm not just talking about the human resistance being crushed by Skynet in a 5-minute end sequence. Something like half an hour to illustrate the defeat of humans and what Skynet actually does in a world where it is the ruler of all that it surveys.