Sid Meier's Civilization V was announced today by Aspyr Media for Linux and SteamOS. The release targets SteamOS on current-gen hardware and is supporting Ubuntu 14.04. Future Civilization V Linux updates will expand the range of supported graphics cards.
This very exciting announcement can be found at SteamCommunity.com. This milestone comes after reporting in October Civ V should be coming to Linux and confirmation of Civilization: Beyond Earth coming to Linux.