It's not often you get some early rumors on what is being done, but today we have a little insight to where Chaos Space Marines are at currently.
First off, it's going to be awhile. Lets take a look at the rumors. These come from a reliable source, but these things are rather sketchy and vague at this point.
Please remember that these are rumors, and this release is a ways out. These are observations from a person who was in the right place at the right time.
via anonymous sources on Faeit 212
Chaos Space Marines are currently being worked on. The models are not even finalized, but a book is being created, and I am assuming that it is a codex. The book is not coming for at least a year, the details are still being changed frequently, both the models dimensions and specific details.
Three interesting sightings
1. A field artillery battery manned by Chaos Space Marines, with tracks and barrels that looked like a quad mortar. Their armor was different , as it had plates on the front that looked similar to that of a Warpsmith. The helmets looked like Mk III
2. Chaos Sorcerer with staves that looked Chaos-y, one that was wearing a robe. None of the sorcerers had horns or spikes sticking out where I would have expected to see them. A group of them casting a psychic power with a Nova Blast effect.
3. New Predator Tank weapons that are not autocannons or lascannons. At least 2 new cannons being worked on, both are boxy with lights down the side, but no clues to what they do.
I saw no legion markings. All armor was a greasy metallic gray, or the subjects were illuminated in a reddish glow. Lights from the eyes of helmets are red or green.
There were no models of cult troops, heretics, or other infantry
There was also something referred to as a Wyrm with large armor plates reminiscent of a Forgefiend. No other details