Taken from link on 40Kforums.
Release date – 1st September (7 weeks he said) and it is a hard back like the 8e WFB Army Books.
There is an Eye of the Gods esque table (Warriors of Chaos players will know what I am talking about) that you get to roll on whenever a character kills another character in a challenge, or a Walker or Monstrous Creature. There is a multitude of gifts (and curses) that your Characters can acquire which range from +1 Save, +1 Toughness, or becoming either a Spawn or a Daemon Prince!!!
Chaos Cultists are definetely in (but we all kinda know that already), as is the ‘Dragon’ – think Necron Night Scythe with the main chassis been replaced by a massive mechanical dragon head with segmented wings sweeping forward and around from it. On top of those there are also:
Dark Apostles – evil Chaplains basically
Warp Smiths – evil Techmarine that can curse vehicles and degrade terrain.
A new Daemon Engine – half way between a Dreadnought and a Defiler.
Speaking of Defilers as they are Daemons they have a 5+ Inv save.
‘Cult’ units are all Elites and are unlocked to Troops by appropriate HQ choices, but there are no Cult Terminators which makes me sad.
Obliterators are exclusively for shooting – so no powerfists. BUT there is a new unit which is basically a close combat Obliterator.
There are 2 types of Raptors now; regular CSM with Jump Packs, and then some kind of Possessed Daemonic Raptors that all come with Lightning Claws!
Possessed are meant to be amazing, and take a lot of benefits from the Eye of the Gods esque table.
There are NO Daemons in the Codex because that is what Allies are for.
That is all I can remember for now. Sorry I am VERY tired. But regardless I have to say I am excited to see the Codex in the flesh and get cracking on some themed lists with Allied Daemons or Guard (for a proper Lost and the Damned army).