AppleInsider is reporting today that Apple's iOS 4.1 beta contains references to several unreleased iOS devices, including "iPod4,1", "iProd2,1", and a curious "unknownHardware" entry. Apple is internally testing the first material update to its iOS 4.0 mobile operating system against a handful of new devices, including next-generation iPod touches, an iPad revision, and an "unknown" product,...