Here's the storyline, which they've had a decade to polish...
Terminator3.com
Storyline from Movies.com: "Destined leader John Conner — the target in Terminator 2: Judgment Day, who now runs a computer programming company — hacks into Cyberdyne Systems' computers and discovers top-secret operation "Skynet." Soon thereafter, two terminators are sent from the future: The T-800 (Arnold Schwarzenegger) is sent to protect him from the T-X, a nearly indestructible female terminator able to change shape and disappear altogether."
I'm optimistic. They've had over a decade to perfect the story. Here's the official website, by the way:
Terminator3.com