Halo 3 comes to you on September 25th...
Entertainment Event of the Year
"Halo 3 is much more than a video game release—it's the biggest entertainment event of the year," said Peter Moore, corporate vice president of Microsoft's Interactive Entertainment Business. "On September 25, we intend to deliver a finale that will go down in entertainment history and leave people around the world with an experience that will be shared and enjoyed for years to come."
http://www.xbox.com/en-US/community/news/2007/0515-halo3releasedate.htm?WText.camp=HR1a-Halo3News&WText.campSrc=Home