AirPlay was introduced with iOS 4.2.x which allowed users to stream audio, video and photos via supported iOS devices so that you can watch them on your television sets (using Apple TV). This feature though came with its share of limitations, the primary being the lack of support for third-party apps, and audio-only streaming from Safari.
Apple announced on 23rd July that they would be delaying the white iPhone 4 and that it would be available later this year. And with only three months left until 2010 comes to a close, Christmas would be the perfect time for Apple to release it.