Colonial Marines supplement/ guide/ thingo.
Nothing announced beyond that as far as I've heard.
They also announced a cinematic adventure focusing on Marines. I think they're both coming in summer 2020 or thereabouts.
A campaign would be nice. How to play in cinematic mode is great but how making this work throughout a campaign is a step I think a lot of us our are looking forward to
The GMs chapter gives a fairly decent high level overview. I suspect that the Colonial Marines book will go into more detail about how to run a Colonial Marines campaign with the following books doing the same for Space Truckers and Colonists.