A Thieves Guild campaign setting...something I know a LOT of people have been hoping to find. It is VERY well thought out. It includes tables for random pickpocket gains based on the social status of the victem. It contains interactions between different levels of the guild, interactions between these different levels and the authorities, and how the populace reacts to them. Things are not as cut as dry as "steeling is bad, everyone reports it".
It is NOT just about the rouge class, either, it includes the ability to be any class and still be in the guild, though it is obviously hard for some (you over there, in the shining armor, with a beam of light falling gently on you, teeth gleaming with the broad, easy smile and your god's name always poised on your lips...the Paladin, I am looking at you here) it still means it is not just a rogue only setting.
Notable NPCs are here, city layout, and much more. It really is an immersive and complete setting for the DM and Players to weave a memorable store around and throughout. I highly recommend it, another great product from Dan Coleman.