One of the big armies that many of use would love to see released would be Chaos Space Marines. It would be a very welcome release, and any news of it coming would be fantastic. With that said, today's little snippet comes from outside the industry.
Please take this as a rumor. This is interesting enough, and may turn out, or I would not post this one. Where I got the info is extremely reliable, and this was the result of a conversation he had with a third person. It also does not mean that nothing will come out for CSM, only that the codex wont be published until summer 2017.
via anonymous sources on Faeit 212
Chaos Space Marines, his understanding it would be published in summer 2017.