It's not enough to be in HD anymore. Nope, seems the next big thing is "3D Radio." At least according to developer iHeart Radio in the U.S.

So what is it? It sounds like very good stereo to me, but they insist it's more than that, a technology that "creates a sense of movement, location and triggers other senses," and "a new-360 degree cinematic sound experience." It seems to have been developed for podcasts.
 
iHeart Hails “Virtual Reality for the Ears”

So how does it sound? You can hear an example here and judge for yourself, although they recommend you put headphones on to hear it at its best.