Being a big fan of AirPlay the news that mirroring of video between a Mac and Apple TV is big. Currently I use AirPlay a lot around the house to play music from iTunes or Tunein Radio to either an Airport Express or an Airplay speaker.
The prospect of being able to do a similar thing to watch movies, youtube or just play a photo slideshow to a big screen TV is very exciting.
If you’ve not seen it in action the video below does a nice job of previewing the features, available in Mountain Lion
Praseela Feltenstein on 
James Wingo on 
