AirPlay is back to the official YouTube app for iPhone and iPad, and AirPlay even got specific controls in the multitasking bar. AirPlay support for YouTube videos was mysteriously disappeared when iOS 4.2 Beta 3 came out. With the release of the iOS 4.2 golden master to developers, the feature is now back, also with a new icon.
AirPlay now has its own set of controls in the multitasking bar, just like the iPod app. That means you can control your streaming music and videos without leaving your current game of Angry Birds. Aside from YouTube and iPod, AirPlay also works in Safari and iFiles. Don't be alarmed if you can't stream to your Apple TV yet, though.
Apple still needs to release an AppleTV software update, which should come out around the time iOS 4.2 is available to the public.