Merrick here...


io9 talked a bit to TERMINATOR SALVATION director McG & co-screenwriter Michael Ferris, who revealed some endings that were once considered for the project (but aren't actually the conclusions they're going with).

We had a jet-black ending. Connor dies, we're in a room with all the people we care about. You take Connor's likeness, you put it on the living machine of Marcus. He sits up, now looking like Christian Bale, takes a gun, kills Kate, kills Kyle, kills Star, kills everybody, eyes flare red, [snaps] the end.
[EDIT]
Ferris: There was an ending of intermediate darkness, in which ... the mechanical Marcus takes over as Connor and goes on to lead the resistance. It's essentially a secret to everybody, except the inner circle, that John Connor is now a robot, is now a Terminator.

...say McG and Ferris in THIS DISCUSSION with io9, which goes on to discuss more about these proposed finales & their eventual banishment.

Also, IESB has posted ten new clips from the film. They originate HERE, or you can view them via the embeds below...