Sorry I was watching the Super Bowl. Yeah Giants.
It covers everything to play. It looks like a complete game with the DM section in the back. There are only 7 career tracks and no rules for crossing careers so I am thinking that you don't. It is more like D&D 2nd Edition instead of 3rd. This book is all about working yourself through the ranks and eventually becoming a Inquisitor.
There is a lot of background info and it talks about a lot of stuff that isn't covered as much in the
40K game such as how the economy functions and the roles played by the different groups.
I have heard people say both ways so I really don't know if there will be a reprint. My understanding is this was supposed to be the Inq, the next was going to be Rouge Traders (in 2009) and the next was going to be Space Marines (GenCon 2010 I think). Those are gone now but they will produce the 4 books they already had ready to go.