I haven't had time to look at the trailer too closely to compare the scenes depicted to ones in (and not in) the book, but I'm sure others out there have done and are doing. Heh. But one obvious observation is that the trailer at least is from a different point of view than the book; in the book, the story is told from Prince Caspian's point of view, but the trailer is telling it from the children's. I haven't done enough reading to know whether or not the film is following suit.
Update: Heh, my husband and I were talking this morning about the irony of this trailer coming out just as The Golden Compass is opening (author Philip Pullman has said numerous times that he detests Lewis' Narnia series). Looks like we're not the only ones noticing this quirk of fate.
So Paul took his stand in the open space at the Areopagus and laid it out for them: "I'm here to introduce you to this God.... He doesn't play hide-and-seek with us. He's not remote; he's near. We live and move in him, can't get away from him!" ~Acts 17