Speculation: If iTunes plays the role of the Fairplay DRM decoder and relied on the channel between iTunes and the Airplay device being encrypted to secure content would it now be possible to use the private key to masquerade as a capable Airplay device and dump a the stream pure and DRM free? Would this work for video enabled Airplay devices?
If so, Apple and this hacker are about to be lawyered hard by the MPAA.