Advanced course formats may need their own data and styles. It would be desirable if Moodle can:
1) Support install.xml within a 'db' folder inside course format.
2) Support backup for this data (probably with backuplib/restorelib similar to modules, in course format folder)
3) Support stylesheets via styles.php in course format folder (as for modules)
I intend to implement this at some time over the next few weeks.
Martin comments about the styles one: 'You just need to modify the style_sheet_setup() function that searches for all these to make sure it also looks in the course/format/xx directories (with a $THEME->coursesheets to control it, documented in theme/standard/config.php).'