I got this from
Dark Horizons:
Arnold Schwarzenegger talked to The Age recently about possibly reprising his most famous role for a fourth time - "Is this my last Terminator? No. I've so many more years left. I'm totally full of energy and thanks to my weight training and cardio-vascular training I'm in great shape. I consider this the middle term of my career. Go out and see the movie. The more successful the movie is, the faster we can make Terminator 4". Don't expect to much in the way of early spoilers for the movie though, the stars confirmed at Cannes that they can't really go into much detail about the film until closer to the release date.
Cool huh? Let's hope T3 satisfies first.