-Grey Knights are the focus of the book. Aside from Grey Knights, the codex contains Inquisitors as HQs, Assassins, and a SINGLE additional non-GK unit.

-ISTs are out, though the models can be used to represent one of the types of retinues available to Inquisitors.

-Speaking of that, Inquisitors will have multiple options for retinues, folding some of the previous codex's more esoteric standalone units into them. ~editor's note: this sounds roughly like what the Archon's retinue structure looks like.

-The Grey Knights chapter fluff is expanded up and defined. It is exotic and not the traditional 1000 men in 10 hundred-man companies type of thing.

-New Grey Knight units are introduced.

-All GK units have psychic powers - including vehicles.

-The GKs will fill out many of the missing allied FOC slots with a full Space Marine vehicle selection (with nice GK equipment options)

-Multiple Assassins can be taken. ~editor's note, interesting as Black Library just came out with a novel focusing on the Imperium's sanctioning of Assassin strike teams.

-GK Terminators are troops.

-The army is not described as lightning fast like the Blood Angels or Dark Eldar but have flexible deployment options to initially get where they need to quickly.

~Standard caveats on these as we are still over a quarter away from release. The big thing is this is very much sounding like a strong Marine book, emphasizing the Grey Knights with minor support options, as opposed to the old codex which let players sideline the Daemonhunters if they desired. This is definately not sounding like an "IG-Lite" book. Have at it.