To the people saying they haven't had a problem with it: Have you ever tried to play an action game via mirroring on Apple TV? The lag is short enough that it might be acceptable for turn based games, but playing, e.g. Real Racing (which I have) is a terrible experience.

This is an AirPlay issue, right? For example, when I go to pause a song that is being AirPlayed to my Airport Express, there is a noticable delay before the song stops playing.