I agree. At least, I hope they don't mess it up. From what I've seen, though, I think it will be cool.
What's the Cullen crest look like, I've heard of it, but they never showed it clearly.

It's very difficult to place everything from the book into a movie, especially the book is ike an encyclopedia (as referred to by Rob in an interview). Stephenie said she was happy with it thus far, so I'm sure we won't be disappointed.

sounds cool but a bit disapointed that they dropped the biology scene cause i thought it was kind of funny how blood nearly makes her faint but she wants to become a vampire

They put in the part from Midnight Sun ... If you haven't read it or heard of it and don;t wanna know don;t read this ... When the ullen's wanna kill Bella. Which is kinda cool cause we get to see it from Edward's perspective!

read an interview on robert pattinson here:
link

Well I think the movie will be 'very close' to the book. I mean not everything can be the same. It's a change from describing things with words and showing it in pictures. So it will be different. It has to be. But I'm really excited about the movie. So it wont be like the books. But I'm pretty happy with all the things I'm seeing. And I know I will LOVE IT!!!

They also changed some other stuff:

- The blood typing scene is going to be cut out, because Edward saves Bella too much.
- A yeah like mandapanda said. There will only be like 2 scenes of the biology class.
- And they cut some of the cooking food for Charlie scenes too
- They also looked like they changed the scene when Bella and Edward touch. In the book they touch in the biology class when passing the slide. Remember?? And Bella got an electric shock. Probably a spark from the crush she had on him. And Edward thought that it was the cold hands that he had. But in some of the trailers you can see that that scene is when they both try ot change the radio.