From the website:
The September Campaign v.2 is a nonprofit free downloadable supplement for Flames of War v.3.
The book will be a "living" resource, meaning that updated versions will be published if needed and a FAQ document will be maintained. There will also be room for discussion and keeping track of news and updates of this project over at the What Would Patton Do forum (the best internet community dealing with FoW).
The book includes 4 armies, 13 Polish lists and 4 Polish characters, 15 German lists and 2 German characters, 3 Slovak lists and 5 Soviet lists. Not all army lists are "competition material", but a majority of the lists should work for tournaments and organized play if you wish to use them that way.
The second part of this project containing all the campaign section content will be released within the next 6 weeks. This book will perhaps be more useful to the whole WW2 EW community as opposed to the OoB book which is very much aimed at the FoW EW community.