Naturally everyone is puzzled as to what it could be. Is it DLC? An expansion? A sequel? A spin-off? Well whatever it is, 2K has said they're "looking forward" to August 21st.
Enemy Unknown proved an eye watering success for Firaxis and 2K Games as it flooded coffers with money, and dev offices with accolades. Overall XCOM fans loved it.
There has been one small DLC expansion (Slingshot) since launch which added a new Council mission, and included a new squad member to deploy. Firaxis has said they have to be careful when it comes to introducing new things as they risk throwing out game balance with new technologies if they're shoehorned in.
"We're looking forward to making an announcement on 21st August!" said a tinfoil hat wearing 2K rep. Hopefully this is at least a significant DLC treat for Enemy Unknown players to sink their teeth into. Enemy Within is for PC, Xbox 360 and PS3. It's unlikely to be a sequel if it's only targeting current gen given how close Xbox One and PS4 are.