Can't believe I missed it, but new info and video of the base mode.
-Soldier customization is insanely detailed
-Weapons can be individually upgraded and modified from the base mode
-Tons of new optional rooms that provide different upgrades and potential items
-Staffing system! Engineers and scientists are recruited much like soldiers, and personnel are individually assigned to projects.
-Soldiers can be trained back at base
-New strategy elements involve searching out resistance pockets to seek out allies and resources
-Soldiers can be re-specced
-The bald council dude is now an informant passing you information
-You'll now be able to gather intel on the current alien short-term goals and be able to make preparations accordingly
-Shen has sadly passed on. HOWEVER! His daughter has taken up his role, and she seems pretty cool, if a bit of a standard Wrench Wench from the looks of her. Not that there's anything wrong with that.
-A new chief scientist has replaced Vahlen, who's described as being lost. Definitely thinking that hunting her down is gonna be a plot point.