Just some screenshots that I filched off of The Master of Orion 3 Guardian, these screens were the ones that really drive home just how BIG a game with 256 star systems is going to be (I think MOO2 was limited to 80? stars). Note that these are older screenshots, so I kind of expect some things to have changed by the time it goes gold.

Overview of the 3-arm spiral galaxy.
First up is an overall view of the galaxy. Looks like this is the 3-arm version of the spiral galaxy (supposedly you can pick different start cluster types such as 2-arm spiral, globular cluster, etc.). It's a pretty wild looking screen, although you can tell it's a game and not a "real" galaxy. But it does make MOO2's square galaxy look out-dated, and the new galaxy formations will provide some new challenges in terms of area-control. (Later stage game in MOO2 was annoying because enemy fleets had such extended range that there was no "border" to your empire.)

Overview of the 3-arm spiral galaxy with space lanes displayed.
Space-lanes are always an aspect that I've wanted to see added to the MOO-universe. A long time ago I played a game where you were placed in a spherical cluster of stars where the only way to get between stars was by using star-lanes. That was a very nice system (allowed you to pan, tilt, zoom the entire 3D galaxy) but the ship combat was horribly flawed which is why I never played it past a day or two. Still, I'm hoping that this works well in MOO3 even though it looks like the galaxy is "flat" instead of true 3D (true 3D tactics are mind-bending, because there is no absolute frame of reference).

Looking for planet 9 out of 12000.
One of the development notes that I saw says that there is a maximum of 256 star systems, each with planets, and planets with moons... so that there's possibly something like 12,000 planets/moons in the game. (MOO2 on the other hand had I think 80 x 5 or 400 maximum planets.) Fortunately, they've added a few layers of macro-control so that I won't have to micro-manage each of those few thousand planets. Instead, you can tag planets as belonging to up to 2 "classifications" and then direct the building queue based on those classifcations.