
There were a few reasons I bypassed iPods when I was in the market for an MP3 player a while back. One of those reasons hasn't changed -- I've never been a fan of iTunes. I wasn't impressed with its performance, generally.
Since I primarily use Linux, the lack of a Linux iTunes client was a problem. Previously, iTunes was almost required for access to the new hotness. The new devices, though not tied to any one format, don't play as nicely with Linux as earlier models.
PwnPlayer is an application (currently in beta) for the iPhone and iPod Touch. One feature of interest is file system playback, allowing easy access to the device's music files on Linux.