Apple designs the hardware and software to provide seamless integration of the iPhone and iPod with iTunes, the iTunes Store, and tens of thousands of apps on the App Store. Apple is aware that some third-parties claim that their digital media players are able to sync with Apple software. However, Apple does not provide support for, or test for compatibility with, non-Apple digital media players and, because software changes over time, newer versions of Apple's iTunes software may no longer provide syncing functionality with non-Apple digital media players.
Unofficial translation: We have the power to hit the kill switch on Pre syncing before you can switch from Pandora to Tweed (which is actually pretty fast). Tread lightly.
What this means for the Pre compatibility actually being shut down by Apple, nobody knows. But that's a pretty strong message, even if it isn't quite a threat. [Daring Fireball via TechCrunch]