And it turns out all your hard work in XCOM: Enemy Unknown was for naught. The aliens did it. They invaded. They won. Humanity is enslaved on its own planet. Probably because Britain or Russia or whatever saw the aliens invading, knew XCOM needed more troops, and decided to pull out of the program at the most crucial moment.
From the press release:
"In XCOM 2, the roles have been reversed, and XCOM is now the invading force. They are hampered by limited resources and must constantly evade the alien threat in their new mobile headquarters. Players must use a combination of firepower and stealth-like tactics to help XCOM recruit soldiers and build a resistance network, while attempting to expose the evil alien agenda and save humanity."
The biggest addition we've learned about so far: Procedurally-generated maps. If you thought XCOM: Enemy Unknown took a huge chunk of your life, just wait until XCOM 2 gives you literally unlimited maps to play on.
Then there are the usual by-the-numbers updates listed: "Five updated soldier classes, increased soldier customization, more alien and enemy types, evolved tactical combat and more."
XCOM 2 will hit this November for PC, Linux, and Mac.