The scnenes from the trailer look like it is right from the book except I don't recall a character as portrayed by Morgan Freeman(aka. Easy Reader) in the book. Of course I read it when it came out a year or two ago.
The most important factor to my anticipation of Dreamcatcher is that it's being directed by Lawrence Kasdan! Hopefully that will elevate it into the realm of great King movies (e.g. Dead Zone, Misery, Shawshank) and away from the schlock (Thinner, Christine). Not to disparage anyone's favorite movies, but c'mon!