the only reason why i got the ipod i have now is because of the ecosystem built around the ipod connector. My car has an ipod connector. It's getting more and more difficult getting a receiver without it built-in, alarm clocks have it, etc.
If I were in the market for a new mp3 player, i would probably look hard at getting a Zune. Leave the ipod in the car, but use the zune for everything else.