After the hype surrounding Gears of War, and positive reviews, Microsoft expects the title to shift one million copies worldwide by Christmas.
Chris Lewis, regional VP E&D said: "Gears of War is a title we know will deliver on all of its promises, and we expect the game to reach 1 million copies faster than any new titles for Xbox.
"This Christmas is an extremely important one for the entire industry... We've put an enormous emphasis on bringing new and exciting titles to market, and Gears of War is a key example of Microsoft's commitment to developing original and immersive titles for gamers everywhere."
The question is, will it be the biggest next-gen game this Christmas, with Nintendo about to unleash the Wii and Legend of Zelda: Twilight Princess to millions of eager fans this Christmas? Will they all be able to get a console? We'll see.
Epic's Mark Rein has also confirmed that more Gears multiplayer content is in the pipeline, but he couldn't (or wouldn't) reveal when it's expected to hit Live.