This is intriguing, and merits continued observation.
I wonder if Firaxis has considered the possibilities of multiplayer modes being added post-release. For instance, a series of 'versus' single-map scenarios where one player controls an XCOM squad and the other commands the alien force. Because this is a turn-based game, asynchronous play would be quite possible (I think
Frozen Synapse and many chess games do this). Another possibility would be larger maps intended for co-op missions (each player commands an XCOM squad)...