Helena Bonham CarterHelena Bonham Carter replaced Tilda SwintonTilda Swinton shortly before filming was set to begin. She filmed her role in 10 days.
The scars that appear on post Judgment Day John Connor in Terminator 2: Judgment Day and Terminator 3: Rise of the Machines are a direct result of the final climactic scene in this movie which the molten hot T-800 scratches John Connor's face in their confrontation at SkyNet Central.
This is the second franchise that both Arnold SchwarzeneggerArnold Schwarzenegger and Christian BaleChristian Bale have both been involved in, without ever appearing together. They have both also appeared in the [Batman] films.
Josh BrolinJosh Brolin was asked to play Marcus Wright, but he turned it down.
Christian BaleChristian Bale is one of seven actors to play John Connor. In Terminator 2: Judgment Day, the adult John Connor was played by Michael EdwardsMichael Edwards, the teenage John Connor was played by Edward FurlongEdward Furlong and the infant John Connor (who appeared during Sarah Connor's dream sequence of the nuclear attack) was played by [?] Dalton Abbott. Nick StahlNick Stahl played the fourth John Connor in Terminator 3: Rise of the Machines. Thomas DekkerThomas Dekker played John Connor in the TV series, [Terminator: The Sarah Connor Chronicles], with [?] John DeVito playing a younger John in a flashback.
In the original The Terminator Kyle Reese asks the police "What day is it? What year?" Marcus Wright asks the same thing of Kyle Reese at their first encounter.
At one point, the film carried the subtitle "The Future Begins." Coincidentally, the film Star Trek (which opened weeks before Terminator Salvation) used the same saying as a tagline. Actor Anton YelchinAnton Yelchin appears in both films.
After Claire DanesClaire Danes declined to reprise her role as Kate Brewster, Charlotte GainsbourgCharlotte Gainsbourg was once attached to star before pulling out due to a scheduling conflict with another film. She was replaced by Bryce Dallas HowardBryce Dallas Howard.
Old recordings of Sarah Connor are played in the film, with lines nearly word-for-word from The Terminator. Linda HamiltonLinda Hamilton voiced the lines herself in an uncredited role.
Director McGMcG asked the cast and crew to read the novel The Road by [?] Cormac McCarthy and Do Androids Dream of Electric Sheep? by Philip K. DickPhilip K. Dick - the basis for Blade Runner - because he wanted them to absorb the bleakness of the world in the novels.
