Usually when I pull out my laptop out at home the kids moan and groan that daddy is about to do work again. But Mountain Lion's AirPlay Mirroring feature instantly changed their minds. With a single click I started streaming photos I took at a nearby park to an Apple TV. Then I streamed a trailer for "Ice Age 4" from YouTube.
Even better, I could mirror a game of “RC Mini Racers” from the Mac to my HDTV, and within seconds the kids wanted to take over. AirPlay Mirroring is so simple to set up compared to Intel's WiDi and any DLNA solution on the Windows side, I can easily see Apple TVs popping up in classrooms and conference rooms.