As far as being a Monster book, then I agree with Arnwyn. The book flopped. However, I really enjoyed the book.
If anyone read the "Year of Rogue Dragons" trilogy, and wondered when those books were taking place, what happed to all the other dragons on Faerûn, this book answers that. In addition, the book gives several stats for dragons, and explains what is happening with the Cult of the Dragon and the Church of Tiamat.
It explains how the Dragonfall war (introduced in the MMIV) works on Faerûn.
In general, it is a "fluff" book, not a "crunch" book. The mini-adventures are neat, but I personally could have done without them.
Oh, and there are only 2 Spawns of Tiamat in the book, so we don't get whacked with a half a book of them this time. (Yes I am still bitter about the MMIV).
The list of dragons in the appendix is really nice for a Forgotten Realms fan.