Apple does not route audio through its Displayport connector

According to Roughlydrafted which has a very sure air to all its remarks, Apple have made the choice of not routing the audio via its connector, the mini Displayport. Thus, on its 24" LED monitor, the sound passes by USB.
This is certainly one of the reasons, together with the cost of the royalties, that they do not propose an adapter mini Displayport to HDMI. Indeed, although the passing of sound is not absolutely important for a monitor, is it is important if one wants to view vidéos on a television set.
We do not know if this limitation is final or if it can be circumvented by new drivers in the future.