Any changes to victory conditions or are they roughly the same as gc2?
Fairly standard, I'd say, except the "Ascension" thing. Can't remember GC2 conditions.
Colony management screen. It's still lacking a planetary governor option, I'm guessing you'll be able to automate the management at some point. As you can see, the amount of hexes to build shit on is limited - though the limit can be extended with terraforming. It's actually not as boring as I originally reported, plus the manager AI seems to automatically start upgrade projects when better versions of buildings become available, so, yay, no need to go through a dozen planets to improve Basic Farms to Advanced Farms - the game will take care of it for you.
2x battlefleets, space station, black hole.
You can stack units in GalCiv3, and form battlefleets. Pictured are two battlefleets of mid-sized ships, which cap at 3 ships per fleet. None of that 1 unit per tile bullshit.
Diplomacy screen, pretty self-explanatory. Can mouse-over the factions to see the modifiers and general attitude towards you easily. Currently seems to be missing the "Relations between empires" mode though, I'd like to see who's warring/hating whom.
Govern screen, opened at Trade Routes window.
Oh yeah, and my current map (still not sure which size it was, somewhere at medium+) is a mighty hex with each side being 90 hexes long. So yeah, maps can be pretty fucking huge. At the start, ships move ~3-5 hexes. I'm guessing this makes the maps "kinda big".