2K Games announces Steamworks support for Sid Meier's Civilization V, the upcoming continuation of the long-running turn-based strategy series, saying Steam will also offer a special Digital Deluxe Edition. Steamworks support will include auto-updating, Steam Achievements, downloadable content, multiplayer matchmaking and more, and they say anyone who preorders either edition through Steam will also receive a free map pack when the game ships this fall. In the meantime, they are offering Sid Meier's Civilization IV: The Complete Edition at a 75% discount. Here's word on the Digital Deluxe Edition and the Cradle of Civilization Map Pack: Mesopotamia preorder bonus:

Sid Meier’s Civilization V Digital Deluxe Edition will expand players’ conquests with the new Babylonian civilization and their ruler, Nebuchadnezzar II (c. 630 – c. 561 B.C.). As King of Babylon, gamers will be able to expand their empire with advanced Babylonian Bowmen to rightfully earn the title of Nebuchadnezzar the Great. Sid Meier’s Civilization V Digital Deluxe Edition will also include an in-depth “Behind the Scenes at Firaxis with Civilization V” video feature, as well as the game’s epic soundtrack.

Gamers who pre-order any version of Sid Meier’s Civilization V from Steam will receive the downloadable bonus content, Cradle of Civilization Map Pack: Mesopotamia, for free when the game is available. The map pack will let players experience the traditional Western and Middle Eastern “Cradle of Civilization.” The pack will include the Fertile Crescent with the Nile River valley to the west and extending east down the Tigris and Euphrates river valleys to the Persian Gulf. Leaders will be able to explore new terrain, cultures and conquests.