We reported on Saturday that the official Total War site had been updated with a new release date (story), but they have incorrectly reported such dates before, so Electronic Arts sent along a press release confirming the August 7th release date. Here's the full press release, and here's a link to an image of the game's box artwork:

Shogun: Total War(tm) Warlord Edition for the PC, the successor to the highly acclaimed real-time strategy game - Shogun: Total War from Electronic Arts, has gone gold and is scheduled to ship nationwide on Tuesday, August 7. Shogun: Total War Warlord Edition will have a new enemy that threatens mainland Japan, as well as an array of new and improved game features. The Warlord Edition will also reintroduce players to the original Shogun title that delivered a revolutionary style of gameplay through its epic size battles. Building upon the excitement of battle found in Shogun: Total War, the Warlord Edition offers the inclusion of Kublai Khan's invading Mongol hordes that sweep across Japan in the greatest external threat the Samurai ever faced. Like its predecessor, the title will allow players to take command of thousands of warriors, each with his own unique Artificial Intelligence (AI) and fighting characteristics, on a quest to unify Japan under the rule of a single powerful warlord.

The Warlord Edition is a stand-alone product that includes the first Shogun: Total War title, which means it does not need the original title in order to run.