A recent Reddit submission points out that Sid Meier's Civilization V might be coming to Linux soon.
Sid Meier's Civilization V is a turn-based, strategy video game in which the player is the leader of a nation or ethnic group and must guide its growth over the course of thousands of years. The game is developed by Firaxis Games and published by 2K Games and Aspyr.
The game's steamdb history page shows that Linux was recently added to the config oslist file. Furthermore, the same page also makes a reference to an "Internal Linux Branch":
branches/portland/description: Internal Linux Branch
282300/name: Civ5 BaseContent Linux
282301/name: Civ5 Executable Linux
282302/name: Civ5 BaseContent2 Linux
Here's a screenshot too, in case the page is updated:
Currently, there's no official news about the game's Linux availability, but these are clear signs that the game will most probably be available for Linux. And of course, since there was no official announcement regarding Sid Meier's Civilization V for Linux, I can't give you a release date.
image via gamenews.zeden.net