I am sorry but I don't understand the quicktime export to apple tv. What is the source data? Can I put in a dvd and export to Apple tv? Otherwise, if its already a digital file, shouldn't itunes be able to read it and therefore it would play on the apple tv?
Can be various things: Content you've created using iMovie, Final Cut Express or Final Cut Pro and now want to convert for playback to AppleTV. Also can mean content that's been ripped from a DVD into another format... of course Apple can't state this in the specs, but that is exactly what it can do.
Don't ask me how I know.