Hi Brad,
First let me congratulate you on the success of GalCiv 2. It couldn't have happened to a more deserving company. Your views on customer support and copy protections have made more than a few of us, rabid fans.
Anyway, I had some thoughts you might be interested in regarding the upcoming expansion. You have mentioned that in it, espionage would be getting some much needed loving. I was trying to think of a way that this could be as fun and revolutionary as your custom ship ideas were in GalCiv2. I was having some difficulty because every game I ever played that had espionage boiled down to the dreaded "Slider Battle", where I put my espionage at a current rating, and the enemy puts their slider at another and the victor gets to play a dirty trick on the loser. This seems kind of souless to me.
What if instead of fiddling with an abstract slider, you actually "Built" spies? Sort of like building a ship. You get a spy, and based on their inherent abilities and how much training you put them through you have a certain amount of "space" to drop espionage modules into. Modules like "Infiltration", "Counter Spy", "Interrogation", "Assassination", "Surveillance", "Computer Hacking", "Escape", "Martial Arts", "Gadgets (helps with other modules), " etc, etc, etc. Once you get better spy facilities you can upgrade a spy to get more "Space" in which to drop better, or more advance modules. Such training might only take a few weeks due to advanced techniques of neurological uploading, or whatever. Anyway, once you have a spy, you select a mission, point them to a target and off they go. They must then infiltrate the target and conduct their mission, or if the heat is on you might have to try and get a message to them to lay low or whatever.
Spies could be captured. Once captured they can be executed, imprisoned or interrogated. Interrogation might result in the death of a spy, but can yield more intelligence about the race that sent the spy. Imprisoning a spy puts him on ice, unless the spy escapes (a small chance based on their ability). Why take the risk of imprisoning a spy? Because you can then either Ransom him in the diplomacy screen, or perhaps do a spy exchange yourself.
Spy missions could be the usual General Intel, Research Theft, Sabotage (either buildings, ships in development or research projects, mining bases), Destabalization, Assassination (the associated planet goes into 'Shock' for a number of turns", or the associated Fleet takes a temporary penalty), or my favourite - Sabotaging relations between races.
Anyway I thought that this would really add a lot of excitement and personality into what is already my favourite 4x game.
Other thoughts about the expansion -
You mentioned that you are going to be implementing User Created enemies. I think this is a stroke of brilliance, as I can't wait to cross swords with the likes of the Klackons and the Mrrshns once again. Now I don't know anything about AI (in fact it seems a little bit like magic to me, even though I am a developer by profession), but I think it would be really exciting for users to be able to alter the stock personalities somehow. Obviously not through code but perhaps by changing various weighting constants (like aggression, economic interest, influence interest, etc, etc). I don't know if this is possible, but it would enable the possibility of hundreds of AI personalities that people could swap on-line. Heck, if there was a way for the game to play itself, people could be addicted to a meta-game in trying to "program" the best AI in a battle-royale.
Another Option that I think would be golden, is that when picking a race to play, you could select "Random Personality". This would basically pick a personality (either stock or user created) and slap the graphic and name to that personality. That way when you see the Altarians, you have no idea what they are like. Perhaps they are psychotic cannibals, unlike the wise and peace loving Dregin.
Lastly - I think Lending out resource bases for 10 or 20, 30 (or whatever) turns would make for some interesting politics. Sometimes I don't need yet another Morale Resource, but my ally might desperately need it, or I can use it as a bargaining chip to keep relations between me and my obnoxious neigbour in line. It would also be a quick and easy way to prope up puppets ... er .. I mean allys when they are getting whacked in a battle. Similarly it would make me take interest in wars where my supplier is doing very poorly. If they lose, I lose the resource that I have been using. This would be a huge means of races helping other races rather than offloading obsolete ships that take forever to reach the front.
This Resource treaty can be prematurely cancelled but it should cause a major diplomatic penalty, and tarnish the reputation of the race that holds the resource if they try and Lend another Resource.
Just my 2 Credits.
Dano