Confirming news previously revealed first on the Web by Electronista, Apple has formally announced a special event set to take place on September 12th. The announcement graphic, which features a dark blue background and spotlight beams crossing the Apple logo, simply announces that "It's Showtime." The presentation begins 10 AM Pacific Time at the Yerba Buena Center for the Arts, located in the same facility as the Moscone Center. Multiple movie-related announcements are expected, including a 23-inch iMac, an iTunes movie store, and a video-capable Airport Express base station. Click through for an image of the invitation, courtesy of AppleInsider.