Stellaris upcoming 2.0 update and Apocalypse DLC are chugging along quite nicely, bringing dozens of features at a hitherto unknown release date. The latest round of stuff revealed during development diaries are a massive change to pirate factions and the addition of nomadic space empires.
The Marauders, as they are known, are a new type of nomadic pirate race who eschewed their planetary predilections long ago, living among the stars. Due to being bred, born, and dead on a spaceship, those guys are capable spacefarers able to output a bigger powerful fleet quicker than their planetary infrastructure rivals. While they are nomadic, they do have home systems from where they operate from, making the whole nomadic thing little more than meaningless lore fluff.
If you plan on making your own Quarian Flotilla, however, you are out of luck -- players are still severely restricted to landfall empires, and there is no word if they ever intend on allowing people to create their own nomadic races. Given the recent changes to player freedom in the game, that is quite unlikely at this time.
Another extra feature added on the Apocalypse DLC is an end-game crisis involving those space marauders. Normally bickering and petty, they can sometimes be united under the rule of a powerful individual titled Great Khan, because to an Earth hammer, every problem is an Europa Universalis-shaped nail. This ridiculously humanly named Khan warlord leads several marauder tribes under one banner and tries the conquer the galaxy, and is up to you to submit as a satrapy or fight the horde.
Non-DLC owners will also get a small change to pirates, who now spawn in any empty system around or within your empire. Pirates still work the same way, launching raids into your territory and needing to be dealt with at their home system to be stopped, but the idea is to stop players from expanding in an invasive manner to get resources and instead consolidating their borders.
Aside from the myriad of "stop players from doing x" changes happening, what worries me a bit about this specific dev diary is the quality of writing. The screens showed feature extremely expository and low quality writing, which is quite unlike the standard set in Stellaris so far. Let's hope this is just a placeholder, and not a sign that Stellaris is indeed becoming a worse game.