With the new OS version, Apple totally changed up the database format. Now it’s based on a whole bunch of SQLite files and there are also a few files in a format similar to the old proprietary one. There are more than likely still hashes in the critical files, and there’s also a suspicious pair of files that appear to be entirely encrypted. The SQLite format is open and certainly better than the old one, but someone still needs to interface a media player to it.
The upshot of this is that a whole new support library will need to be written or large changes in libgpod need to happen to support the new SQLite format. The DBVersion hack also isn’t going to work – either someone needs to reverse engineer the complete hashing algorithm (and maybe that encrypted file stuff), or the MusicLibrary binary on the phone needs to be patched. So, if you’re currently syncing music with free software, you’ll want to hold off on upgrading to 3.0.
Patching the check out of MusicLibrary looks trivial enough, so although it’s not as easy as the DBVersion hack, it isn’t a real showstopper. The hash algorithm looks the same as the old one, or at least quite similar (and just as badly obfuscated). Those encrypted files do scare me a bit though.