[bluthru]

AirPlay requires a GPU that has hardware h.264 encoding. This is so there isn't a performance hit to compress and send video to the AppleTV.

You can download AirParrot if you'd like the functionality to work with a small performance hit.

[mortenjorck]

Can you at least send arbitrary video from apps to it, e.g. an h.264 video playing in Safari (as you would on iOS)?