Release date:
Originally January, now looking more like March.
Organisation/fluff:
Codex: there is much less focus on Inquisition aspects, and no Sisters. No Allies. A Grey Knight army.
The organization of GKs chapter being fleshed out has opened a number of new "roles"
The relation of Ordos Malleus to the Inquisition is also expanded upon
Officio Assassinorum also has an interesting fluff piece... very short
Special rules:
Combat squads were an option
Some interesting Psychic abilities. just about all squads have psychic options. Heavy on they disabling side.
Not a lot of Mechanised. But quick to deploy.
Army wide. Daemonic Infestation makes summoned demons less instable?
The basic Grey Knight marine profile looks very similar to a normal marine sergeant.
An ability named "Out the Heretic" which could be used against non-daemon forces causing one unit to "count as" daemons.
"Shrouding' basically unchanged...also known as nightfighting...one source suggests possible grant 6+ cover save
'Rites of Exorcism' daemon units charging as if into difficult terrain.
'Aegis' enemy Psykers within 12" take psychic tests with +1d6
Chaos icons work to oppose Grey Knight units teleport ability. A unit with a chaos icon will block the ability of Grey Knights to teleport into battle within the icons area of influence. There may also be other items that hinder this deployment tactic from other armies as well.
Wargear:
The new codex has new options (weapons, equipment, etc.) that will be included in those box sets.
Also, I understand there to be a standard 1 special weapon per 5 man squad, plus special options for the upgraded leader.
Corrected Psycannon profile:
24" A3 AP3 S6, no invulnerable saves, pinning test for units or models with psykers.
or 36" H1 AP4 S5 5" blast, no invulnerable saves, no cover saves. (does not cause psyker pinning)
Incinerator, no profile changes noted: S5 AP4 A1 template, no invulnerable or cover saves.
Nemesis Force Weapons lose the changing abilities based on rank of user. standardized A Nemesis weapon is power weapon with special abilities vs Daemons. Nemesis Force Weapon will be +2S across the board as now, but powered armored Grey Knights will all count as power weapons, and terminator armored Grey Knights will all count as force weapons. Then on top of that, all nemesis force weapons gain additional capabilities vs daemons. Plus unit leaders may have master crafted nemesis force weapon and Grey Knight anointed armor
Annointed Armor: All Grey Knights wear ornate armor which has been blessed and anointed to provide additional protection both physically and spiritually. Any Grey Knight may always Re-roll any failed armor, invulnerable, or cover saves. Annointed Armor is not wargear. Has point cost. Works with Storm Shield.
The rumor about "Annointed armor" got some additional legs with a small twist. Looks like this could be granted to a unit containing a Gk chaplain. Much like other chaplains elsewhere grant re-rolls on charges, the gk chaplains are rumored to grant counter attack and re-rolls of armor saves...caveat being the reroll is only 1st round of cc... It's a complex confirmation, and taken alone I'd pour salt on it, but given I've heard of the anointed armor prior and recent codexes have some charge related chaplain ability...I thought I'd go ahead and post it. It's definitely taking more realistic tones...
New options for Dreadnaughts including librarian. psycannon arm. Purge weapon...large pie plate, special abilities include forcing instability test for daemons, including Daemons of Chaos armies, pinning in other armies.
Do not hold too tightly to past structures and expectations.
Terminator Grey Knights filling roles in two slots possible, Heavy and Elite.
Grey Knight terminators will have access to the standard marine upgrades, plus nemesis force weapons, incinerators, psycannons, etc., of course.The cyclone launcher for them will be arm mounted like their Storm Bolters.
Inq lords are HQ and unlock Inquisitorial Storm Troopers as troops, otherwise they are elites they can take chimera or valkyrie as dedicated transport
Inq lord retinue looks more like imperial guard command characters with some seritors thrown in
Temple Assassins one entry in elite, one stat line, options allow for customization into temple variants...but the actual temples are only mentioned in fluff, so some special rules look lost
Demonhosts look to be out
In troops we have imperial guard conscripts...like an imperial guard platoon, but conscripts only
Death cult assassins still elite, larger unit sizes
Penal legion squad in troops, different than imperial guard codex entry
Chimeras or valkyries as dedicated transport only, and only imperial guard. Valkyries only dedicated transport, no vendetta option
Hellhounds in fast, same as imperial guard, but not variants
Deathstrike launchers in heavy, same as imperial guard...replacing orbital strike
Storm Raven. Options for BA, GK and ??? (note, other sources say that a BA second wave containing storm raven and librarian/furioso dread are slated for a separate January release)
Also, some weird dynamics in the ruleset if you have both Inq and Grey Knights HQ present. No details
Including Special Characters, not including variant units eg. exterminator/demolisher
HQ: 8-9 entries
Elite: 6-7 entries
Troop: 6 entries
Fast Attack: 7 entries
Heavy: 8 Entries
Thanks to Stickymonkey for the information. Also thanks to anyone else I did not know contributed to the info, since information gets rehashed and re-posted many times over. I have more information, I will post this later.