I have really been looking forward to streaming my mkv's to my aTV3 using AirPlay in Mountain Lion. The thought of using my uncompressed/higher bitrate mkv's instead of compressed/lower bitrate mp4's seemed like it would be a great thing to have. Then it occurred to me, AirPlay transcodes everything to h.264 on the fly for the aTV anyway. So are you really gaining anything over transcoding it yourself? In fact, might it not yield a lower quality transcode by having to do it on the fly rather than a High Profile Handbrake transcode? The only advantage I see right now is not having to have 2 sets of movie files, mkv and mp4. Am I off-base here?