Paul, I think this is a good idea, also because it could be coupled with some sort of backup system.
Basically, one may create a copy of all the 1* fileslocally and simply compare them with those on the player (size, date, last access, or whatever), and download only the new ones. If this is fast enough and gets implemented, then the same method could be used to create a backup locally of all the actual mp3 files and operate on them in the same way. It would be the user to chose whether to simply create the dbase locally or have a backup session.
Just my 5 cents