TimW

EDIT:

OK, the preview is only two pages doesn't have too much information, though what it does have is quite important.

New Mechanic: Corruption Level. Essentially, it's a campaign mechanic if you complete missions in ways which might be frowned upon by the Imperial Cult, e.g. trashing a shrine.

Corruption level affects wargear options and how NPC allies react towards you.

Campaign: There is a Spess Marine campaign in which you fight against chaos. At least part of it takes place on Meridian, and the Angel Forge map. The text does not say this is the only campaign, or even if this is the final campaign. It just describes a mission the writer got to play. In which he was Space Marines against CSM. It might just have been something they knocked up to show the press or a WIP of the final campaign.
Relic quotes suggest it might be more narrative driven than the previous one.

In this campaign, you will likely meet

Confirmed Units:

Regular CSM, obv
Chaos Predator
Bloodletter on Khorne Juggernaut
Chaos Dreadnought

The Chaos Marines in the screenshots were in Night Lords colours, though of course is a . SM were Blood Ravens.

Release Date: Spring.