As noted by 9to5mac last night, AirPlay went missing on the iOS 4.2 GM for iPhone 3G. The feature was there in the previous betas and was working fine, allowing users to stream audio (no video to Apple TV yet, it needs an update) to AirPlay-compatible devices.
Apple apparently removed the feature when releasing the GM build on November 1st:
After speaking to multiple developers and users testing out the iOS 4.2 betas, we have determined that AirPlay did in fact work on the iPhone 3G at one point, meaning the AirPlay functionality was definitely removed from Apple’s two-year-old iPhone at its GM stage. The reason this is an issue is because Apple states, even on their own website, that AirPlay is supported on ALL iOS 4 devices.
On Apple TV’s official page, Apple clearly states that AirPlay works an all iOS 4 devices, and the iPhone 3G is capable of running iOS 4 – actually iOS 4.2 will be faster and snappier on the 3G than previous versions of iOS 4. So why did Apple remove the feature? Perhaps it’s just a GM issue and it’ll come back by the final release. Perhaps they want people to upgrade to newer models?
We don’t know. The final release of iOS 4.2 will speak for itself.