The new features appear to include:
Support for multiple playlists
Improved music file sorting
Support for WMP10 synchronization
Smart play function, which allows one to set the time to stop playing, the length to play, etc.
Personalized ranking of songs up to 5 stars
Displays a picture during playback of each individual song.
Displays the next three upcoming songs, even in random play mode.
The ipk includes a preinstall that checks to make sure that the model number="SL-C3000". Otherwise, it doesn't appear to be dependent on any libraries or external files that are not already included in the ipk.
One important note is that it overwrites the old musicplayer files (bin, plugin files, help, etc).