Well, first off I liked reading this book because I feel better knowing there are other nerds out there who want to know all the details about Avatar and discuss them at length. And, he does a good job at this. I have no idea how he got the original script or details about the deleted scenes (why didn't you tell us Alex?) but they are really interesting. I wish some were back in the movie - especially the drama around the school massacre that another reviewer mentioned. The trudy / norm relationship - yuck, glad that was cut! It was great to read about this and his thoughts about why these scenes were cut and how certain themes ran much deeper than I had really noticed in the movie. Anyway, I was glad to have read it overall...and what's below are just critical statements because they might benefit other readers who are confused / put off by similar issues while reading (but shouldn't dissuade people who are interested in the movie).
There are a number of copy editing problems and minor mistakes that aren't a big deal, but they are distracting as you read. First, I wish the deleted scenes were more clearly divided out in the book - just with a horizontal bar or something. Sometimes he doesn't make it clear that a scene was deleted (until after describing it) and so things can get confusing. He calls Jake "Jack" in the same sentence he says that he had 6 months before the bulldozers arrive (it's 3 months - which he gets right later). There's a funny statement about a hair queue being some "American term" - lol... no... maybe you should have checked with an American! I just laughed out loud at that part though. Obviously, it was nothing I took offense to because I've probably said the same things about British expressions. Also, along these lines, I wonder if the UK (and Europe) got a different cut because I know the "well of souls" was not called that... it was the "tree of souls" - and I have the DVD and am positive about this. There were a handful of these strange things like that in the book leading me to wonder if Europe got a bit of a different movie for some reason. What happens with the Dragon is also confusing from the book... I couldn't tell what was deleted or what may have been different in a European cut. Jake gets it to crash land - and not on any Na'vi that we know of.
I think the order could be fixed as well. Largely, it is in the order of the movie - but it does have weird points where it jumps ahead. For example, I agree with the other reviewer there is too much of a focus on sex, and this is what screws up the order a bit. The bestiality stuff was a bit weird - I never got that from the movie at all. He describes the sex scene long before it happens...then describes it again. This happens with a few scenes.
Also, there are a lot of references to Terminator and Aliens. I have only seen Terminator 1, so I was a little in the dark here. I wished he would've given more of a plot summary of these movies so I didn't have to look them up on wikipedia (which he did quite a bit in the book, which I found strange for an author doing an in depth analysis...wikipedia is kinda a big giant regression to the mean & a lazy way to get data... but still, it's a good book & I'd be too lazy to ever write it - so I don't mean to throw stones.)
I think it's an interesting read...and I'd recommend it to anyone interested in the film. Oh also, you may not agree with all his analyses - but just know you're getting his opinion & speculation on many issues (e.g. why certain people have certain names...who knows if he's right?) This is not James Cameron's view...so that's just what you get for reading this vs. waiting until whenever Cameron's commentary DVD comes out.