For a start, as you may have seen from all the millions of posters about, Jacob looks brilliant for the part. He's bulked up a lot, and really comes into his own in this film. This is obviously going to help with the next two films coming up as he plays a crucial role. Edward takes a step back from this, but still holds his charm which many girls seem to love (Team Jacob all the way).
It's a little different from the book, but not in a bad way. The book was probably the weakest of the 4, but it's been taken to another place in the film. It's got a lot more tension in this - And not the sexual kind, although that is not lacking. There's a lot more aggression and fighting which is brilliantly done, and the fight scenes are pretty realistic looking. And in terms of the casting, just like the first one, every character seems to resemble the one in the book perfectly. We're introduced to Michael Sheen who plays Aro, Dakota Fanning who plays the pretty evil Jane, and the rest of the Volturi gang. Their red eyes and evil glares take you back to the books, along with most of the other scenes in this film.
I found in the first Twilight film you lost a sense of how great the book was, but within the scenes of this you get given an image of what you could actually see when you were reading the books. Of course, you're only ever going to understand the fascination with these films if you've read the books; they're still the true winners of this series.
The sense of community you get in the cinema with this film is actually quite bizarre. Everybody seeing it in the first week has clearly been waiting for it to come to the cinemas, so expect screams, laughter and excitement when you're sitting there. It's brilliant really, you can see how popular these films and characters really are, and how much of an effect films have over an audience. There was one point where Jacob whips his top off and I said "I'm not ready for this" because it was too much for my poor heart to cope with.
So overall, if you are a Twilight fan see this film! You could easily sit and watch this over and over again. You'll fall in love with at least one of the characters, and get taken back to the books once more. It's fun, cool and totally cheesy.