It would be nice to have a button to delete the previous library without having to individually delete all the files including the ones containes in the artist, genre and year subdirectories. (This would make it alot easier to do from a touchscreen also!)
Options would be nice for instance deleting music but not video and karaoke, etc - but I think heading down that track would really clutter the config, so maybe just an option to delete all would be nice.