I've just got the latest source book for the Iron Kingdoms RPG, and boy is it awesome.
This is only going to be a quick overview, as I haven't had enough time to read in depth, but a full review will appear in time.
The book is produced the same way as the core book, being a full colour hardback. While I haven't counted the pages yet, it has roughly the same page count as the core book, while containing much more fluff over rules!
The book is divided into 6 sections, covering the major kingdoms of Western Immorean. Not only does each section have a map and an outline of the kingdom's history, but it also includes geographic information, as well as the major mover's and shakers.
Each section also includes a players section which provides new careers, abilities, spells, gear and warjacks relevant to the nation. Anyone who wanted to play as one of the units from the wargame now has everything they need.
Overall this looks to be another excellent book. Only one gripe so far, and that their is a players section at the end of each nation, which while I understand works well layout wise, but is a pain for referencing. Especially as some of the abilities and spells are available to other careers.
However, I'm really looking forward to devouring the book, and will give a fuller review once I have.