iTunes 10: "Itunes Library.itl" Cleared, Nothing Appears in iTunes

I've seen a few other threads describing a similar problem, where no music, or any other media files, appear in iTunes after upgrading to iTunes 10. I'm seeing the same thing, but can say with near certainty that it is due to the fact that my "iTunes Library.itl" file has apparently been erased/recreated, either during the installation of iTunes 10 (which I did yesterday afternoon, about 16 hours ago) or when I first started iTunes after the installation of iTunes 10 (about 30 minutes ago).

I can see "iTunes Libary.itl" on disk, but it is only 4KB in size (an earlier copy - a corrupt copy, unfortunately - is about 4MB). Similarly, the "iTunes Library.xml" file is only 12KB is size now (an earlier copy is over 20MB).

While I may be able to recover using the earlier version of the xml file, and can definitely add everything back manually, I will certainly have lost those songs/playlists/other data that I have added since that file was last updated (a year ago). Not to mention the time it will take to get everything set up again.

I guess I don't have a specific question, but am maybe hoping beyond hope that someone has some way I'm not aware of to get my iTunes Library.itl file back without an existing backup. A long shot, I know...

I know it's on me to have backed up those files prior to upgrading, having experienced corruption issues before - never during an upgrade, though. But I wouldn't have expected Apple to put out an update that completely erases the iTunes database.

This upgrade, however, is certainly leaving a bitter taste... From here on out, I guess I'll have to take that extra step to back up the database files every time before upgrading. I'll also not be upgrading iTunes on my wife's PC any time soon, either... Necessary precautions, perhaps, but very disappointing ones to be forced to take.