I'm quite stoked for this.
They are basically adding a real time editor to MP, allowing one player to dynamically influence a mission. This has been around for A2 and A3 in the form of VTS and MCC, but having it natively should be sweet, especially as apparently it's mission independent?
Also, dynamically spawned butterflies. Yes please?
More details from the devs:
It's an extensible MP framework, which enables (at least) one player to assume the role of a Game Master (AKA 'Zeus'). GMs can create and edit entities (vehicles, units) and logic (objectives, waypoints) on-the-fly.
On top of this framework, the DLC itself comes with some dedicated scenarios, where Zeus/players have some specific non-adversarial goals (like a simple sector control or deathmatch).
Zeus multiplayer also works with custom player-created scenarios, which is where we think its true potential lies. You can take any scenario and build upon it, or simply curate it as an admin.
We hope to flesh out the concept, and answer some of your questions on our Livestream, Saturday February 15, at 17:00 UTC.