Neonboombox is hiding in shame from the glory that is ICEł.
ICE3 is a great program, but is fundamentally different in execution from NeonBoomBox. NBB uses the iTunes library structure and so is a bit more intuitive from the start, and you don't need to rethink your music management. Also, it can access your playlists directly, which is nice. I'm glad for both and I hope both can keep going.
I personally appreciate NBB's more minimal user interface, but I know most people don't agree with that. To each their own, I suppose. Having said that, I'm using ICE3 more recently because there's a couple of bugs I would really like to see fixed in NBB that keep me from using it all the time.