During the PAX East 2013 panel hosted by Firaxis, after the developer showed off the iOS version of XCOM: Enemy Unknown (which Firaxis claims will be 100% faithful to the PC version), a short audio clip followed "Hello, Commander", and began to warn of a new threat before getting cut off by static.
Could this be a tease for a remake of XCOM: Terror From the Deep? Firaxis is coy about the mystery project - stay tuned.