I hope that this serves as a proper boost to social characters. One of the least fun things about Black Crusade is how little is in the books for them. Even the Investigation rules in Tome of Fate didn't really introduce anything new and were more of a "how-to". So I hope that we get good social combat, a system to handle cults and the different kinds of cults, new things to do with lore checks and other skills, and some items/new talents for those who fill such roles. But I understand that FFG has to print what the majority of people want.
Which from this thread I'm expecting to be lots of new weapons, psyker powers, descriptions of areas, history of Slaanesh, and possibly a small 5-10 page section on social combat/seduction.