Sigourney: Avatar has 2 parellel stories...

Sigourney Weaver recently stated (Hit) that James Cameron's Avatar will consist of two stories running together:

“I’m not allowed to give too much away, but we have parallel adventures. There’s a younger person’s story and a smaller, older person’s story all happening at the same time. All my scenes are with [Worthington]. It’s really a lovely relationship”.

She goes further into how sweeping the movie is - ambitious and romantic. "I can't wait to get back."

...neither can we Ripley. Err, Sigourney. :-)