I agree with Kai; you should definitely read the book! It's so good. I'm planning to re-read it myself since it's been years since I read it, and the details are bit fuzzy for me.
I hope you weren't too spoiled! Finish it; it's really good! I love that part in the trailer, too. I also love the different shots of Susie's personal Heaven. They're so beautiful! I also love the part where Susie and her father are reaching toward each other's fingers in the window. Got me kinda teary for some reason.
No problem! Saoirse's great! She was in Atonement before, and she was superb and nailed her role as Briony, too!
What's your link to your LJ community? I would love to check it out!