As a result of the GNOME Summit, I have finished my first Banshee plugin: Lyrics.
The Lyrics plugin will various sources and display the lyrics for the currently-playing song. It isn’t network-aware yet. It doesn’t cache lyrics once they’re found. It only queries one source (the next release will query multiple sources). It’s functional enough for a first release, though.

Thanks to Aaron and Jorge, who listened to me talk about lyrics half the weekend.