A heads-up: Amarok File Tracking can now use MusicBrainz track identifiers for its embedded IDs. This means people that have used Picard to tag their files but not amarok_afttagger can still get some embedded AFT goodness! It also enables an interesting "mode" because it essentially enables song tracking vs. actual file tracking (which you may or may not want, depending on your particular needs).
Full details are here.