updated 05:45 pm EST, Mon November 22, 2010
Phone increasingly excluded from iOS 4 features
The iPhone 3G is indeed going without support for AirPlay, one of iOS 4.2.1's most critical features, Apple disclaimers confirm. AirPlay compatibility exists for almost all other iOS devices, such as the iPad and the second-generation iPod touch. The 3G is the oldest Apple device capable of running any incarnation of iOS 4.
AirPlay lets iOS users push music, photos and videos to an Apple TV or another piece of compatible hardware. Its absence from the final iteration of iOS 4.2.1 for the iPhone 3G is notable mainly because the option was present in some pre-release firmware, suggesting that it was pulled as a last-minute decision. Apple has however increasingly marginalized the 3G in firmware updates. Aside from lacking support for features like AirPlay and multitasking, the 3G has also been denied access to some less intensive iOS 4 components, such as Game Center and even homescreen wallpapers.