Models:
The box sets should all be plastic.
The GK models are ornate.
The biggest issue you'll find with the Termintator Armor is scale. The new plastics are in scale with the other Terminator models. The metals are old scale sized. Its a noticable difference.
Once painted, the new models have better depth of detail IMO. And more small details not present in the metals. This is in both Terminator and Artificer Armor. The best examples to look at are the Blood Angel plastics to understand how much detail can be crammed onto a figure, but still look good.
Plastics:
Storm Raven. obvious choice. 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) I've had personal conversations with direct individuals, which would surprise me if the SR model was not a keystone of this release. I've personally seen a few mockups of the SR from the modelling teams, many more from the art team. I know what the final selected design is. It looks better than I imagined.
Terminator knights: 5 pack, Paladin upgrades, squad upgrades. Psycannon, Nemesis Force Weapon, Supposed options for all will be on sprue. Plus Nemesis Force Weapons will NOT all be halberds. But the exact nature of them was not revealed to me. If this pans out we could see a lot of weapon options in the sprue...a lot more than would be used. Assault Cannon, PsyCannon, Incinerator, Storm Shields, Thunder Hammers, Nemesis Force Weapons, Cyclone launchers...seems like a lot to jam in, but if we look at SW and BA boxes those were loaded with bits.
Powered Armored knights: 10 pack, justicar upgrades, squad upgrades, extra bits. Nemesis Force Weapon, psycannon, incinerator, banner?
walker: There have been some rumors of a Grey Knight driven walker. I have not personally seen this in any incarnation. However, there is a boxed walker of some type. I suspect this is a dreadnaught box set that will also have bits for BA. (see above) I've seen other people posting rumors of a penitent engine style walker, with a PAGK driver...I have absolutely no confirmation of such a beast. However, if GW wanted to avoid the cries of "GK dont have Dreads, it isnt fluffy" that could be a way...
Tank: I have not seen mention of a Grey Knight troop transport. Rhino based with psycannon options has been in some Posts. I list this as possible, but unlikely, 4 box sets of this size are about par for a release, 5 would be a surprise.
Blisters:
New Stern
New Chaplain?
Justicar upgrade character
Paladin upgrade character
Inquisition character
2 other blisters unknown contents
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.