Blueprint for the future
MoodShuffle can be made better with more meta-data. It currently uses what is in iTunes. The long term plan is to use this site as a wiki to serve additional meta data on a per-song basis.
SongLink will allow you to link a group of songs together. If you have ever listened to a random playback mode, and a particular song has an intro, and one or the other plays, it is annoying to not hear them paired together. SongLink solves this problem.
Saving the mood. Folks have requested that there be an option to save a given mood-session. This will likely be added in the form of an iTunes playlist.
Honoring iTunes preferences. The next version will honor your 'Skip when shuffling' settings.
Seeding MoodShuffle - The idea is that you are currently listening to a song that you are in the mood to hear. So you launch MoodShuffle, and instead of immediately taking control, it lets the song play out, and uses it to seed the Mood Engine for further songs.