I would love to see the Music section expanded with a few new options. This includes...
Sometimes I'm in the mood for a certain genre of Music (such as Acoustic or Live recordings). Being able to browse tracks by Genre would be nice (because sometimes you just want to Rock out).
Other times, I just want to listen to a predetermined list of songs. Not sure how this would be implemented (navigating by Artist / Album, pressing Play on song adds to Playlist?).
Visualizers are one thing. Actual videos is another. Having a section for Music Videos would be great. In my opinion, Music Videos should be in the Music section as they're called "Music Videos", not "Videos Music".
I like being able to display the lyrics of songs on the screen, but they're static and you have to scroll through them manually. Boxee is visually stunning, so imagine how nice it would look having the lyrics of the song you're listening to scroll on the screen? Maybe in the style of something like this?
If everything could ever feel this real forever
If anything could ever be this good again
The only thing I'll ever ask of you
Okay... so displaying with plain text it tough, but I'm sure you get the idea. I haven't really research what would be needed or if this would be possible, but I'm sure there's a online database of karaoke files much like there are for Movie titles, TV Show descriptions, and Music lyrics. Either way, it's just a thought.