I saw that mountain lion now allows full screen mirroring over airplay to an Apple TV.
For awhile when I want to play something on my tv from my computer I've just run an HDMI to DVI cable to my laptop, especially since some things I can't stream through my PS3 (doesn't like anything purchased in itunes) And I know the Apple TV would not stream just any file from my computer.
But since I can mirror audio and video am I now able to stream anything to the Apple TV by playing it on my laptop screen and using mirroring?
I just saw this thread which would imply that even if this would work, it won't since both my Mac Pro and laptop are pre 2011 macs.