I sat down for a bit and chatted with Chris Stewart from Kerberos Productions recently about what we can expect when SotS2 hits. He had a lot to say. The major goal in the game is to show that there has been some progress in the universe. So they are taking all the good 
things from the original and bringing them into the new game. Then they are taking it and turning it on its ear. Hints were dropped in the first one of things to come. One of those things will be the seventh race in the game, a Liir-Zuul Alliance. The Suul’ka will also make an appearance.
Now while the gameplay will remain, including the randomized technology trees and 8-player multiplayer they are changing some other things. A new ship class will be introduced, the Leviathan. The galaxy will be smaller but that’s because you will have to fight for control of solar systems by taking control of the planets and moons within it. So while the galaxy might seem smaller, it will have more depth of gameplay to it.
Territory will become a major factor in the game with new political mechanisms being implemented. 
Essentially you will be able to conquer solar systems, then combine them into a governmental province for ease of administration as well as local system guidance.
There’s also going to be a sort of Galactic Encyclopedia that will allow you to delve into the rich history and ocean of information that surrounds the galaxy and its inhabitants. This will give those that wish it, a detailed background on multiple facets of the game’s universe.
Now if you played Sword of the Stars you know that Kerberos did a good job of continually expanding the game’s story and content through add-on packs. That will return I was told and we might even expect to see, one...more...race.
