You knew it wouldn't last. Apple has just issued an iTunes update that kills Palm Pre syncing capabilities.
Palm had engineered some oh so clever programming that tricked iTunes into thinking Pre was an iPod, hence allowing Pre users to sync and manage their music sideloads via iTunes, just like iPhone/iPod users. Alas, Apple has said enough is enough via this little footnote in the iTunes 8.2.1 update:
"addresses an issue with verification of Apple devices."
That's geeky legal speak for, "Kills that nonsense that some ex-Apple execs were all happy about for a few weeks there." Pre owners can still rock the iTunes-based syncing via doubleTwist, and who knows what Palm might be readying as a response.
For nostalgia's sake, here's the video I made a month ago or so showing how iTunes and Pre used to play nicely together.