I recently brought my wife's Ibook along on a road trip for music and movie
playback. It took me awhile to figure a small great feature. When Itunes
switches songs, it does a short 1-2 second cross fade between the tracks. This
is amazing once it is in action. It makes a collection of randomly played back
songs meld together into a single soundtrack. It is a simple and sophisticated
feature.

I also noticed that pressing the stop button does a quick fade out, instead of
instantly cutting off. This also has a very natural feel that I like.

These are really the only things about Itunes that I prefer over using
Rhythmbox. I'm not sure of the difficulty of implementing this in gstreamer, but
it should be well worth it.