Amarok has similar functionality. With the added benefit of song queueing. So if I want to listen to a particular song without killing my playlist it's easy. An

Amarok has similar functionality. With the added benefit of song queueing. So if I want to listen to a particular song without killing my playlist it's easy. And queuing a particular song to be next can influence the dynamic playlist allowing me to have one playlist that changes throughout the day to match my current mood/desires. Itunes doesn't have this feature and doesn't seem likely to anytime in the future.