I'm on a Mac with iTunes 10. I have a bunch of MP3s that I have listened to for years, some of the play counts are in the hundreds and most of it is rated. I am going to rip some of the songs I have from their original CDs but I don't want to lose the metadata. Is there a way to easily and quickly backup and then restore the XML metadata?
It looks to me like iTunes 10.0.1 stores that metadata inside the ~/Music/iTunes/iTunes Music Library.xml file. If you open it with a text editor, you'll see a big list of XML keys that include such things as the play count and the file location path.
The existence of a File Location Path key suggests to me that if you re-ripped a song and stealthily dropped it in the same place in the iTunes Music folder with the exact same name as it's predecessor, iTunes would be none the wiser. The metadata would remain intact.
I do see a bit rate key in this file. I assume you're re-ripping the CDs to get a better bit rate. I don't know if this key would have to be edited to reflect the new bit rate. I'd say give it a shot and see.