I was watching the E3 demo video and noticed that the Underworld's corruption of planets and trade routes seems to take about twenty seconds. I know that things were probably sped up a great deal for that demo; however, I think that galactic map speed really needs to be slowed down. I always run EaW with galactic play at its slowest setting, but even that I think is far too fast. There should be time to set grand strategies in motion, to react to enemy movements, to feel helpless when an incoming fleet will beat any reinforcements you can send, to build up some anxiety when I have an attack fleet en route and I don't know what ships might arrive at their destination after I gave the order to move out. I want to feel like I'm really throwing galactic fleets around, and I want there to be some more seriousness to launching an attack on a planet. I'd suggest at least doubling build times for space units and tripling travel times on the galactic map in the expansion.

Similarly, I don't think the Underworld should be able to corrupt a planet instantly. The speed of corruption of a planet should depend on the number of Underworld "corrupters" present and Imperial or Rebel forces present. It should also take a longish time (especially since the Underworld can essentially do this to take over planets without launching a resource-intensive invasion) to give the enemy a chance to notice and try to react. Maybe they react successfully, maybe they don't--but they should have a chance instead of basically losing a system as soon as the Underworld moves a sabateur there.

Hopefully there will be some sort of counter to the Corrupt ability, much like in Rebellion you could target your own planet with an Espionage mission to see if the other side was running any operations there. I'm thinking that Bounty Hunters will probably play some role in removing Saboteurs and the like, but it would be nice if the hero units could do this as well. I imagine Darth Vader would be useful in rooting out subversive elements...