The subject was AirPlay, which is a specific technology that allows users to play video on their iPhone/iPad on their TV through AppleTV. Can you rip off a video into iTunes and make AppleTV play it over wi-fi, but it's not AirPlay.
AirPlay actually has its origins in AirTunes, which was originally only accessible through iTunes. These days there are even third party senders and receivers for AirPlay, so in principal you can use AirPlay without actually using any first-party Apple software or hardware.
As i386 said, I don't think Torrent -> HandBrake -> iTunes -> Apple TV is a path many Apple users will take. But I guess it's AirPlay. :)