That's it exactly. The Alpine will display your playlists and songs directly on the head unit itself. On certain 2004 models, Apline added a jog wheel, probably to mimic the iPod interface on their head units.

The other nice thing about having the head unit do the song controlling is I can use my stearing wheel controls to switch songs. Since I prefer to shuffle across either the entire iPod or large playlists, being able to use the stearing wheel controls is a very nice bonus.

While the solution in this thread is really well done (and thanks to everyone for documenting it) I personally am waiting to look at the Alpine solution before making up my mind as to which way I am going. Probably leaning towards the Alpine solution - it would be much cleaner, less stuff hangin around the dash.