I'm afraid I never turned on the stereo system. In part I was more focused on the noise (both motor noise and the infamous added noises). I also had Mark Perry with me and was chatting with him the whole time about other features and questions about the program- and was definitely more focused on the "EV specific" stuff.
I could swear it was an actual iPod dock (and as Mark flipped back the cover to show me, he said specifically "iPod", not "aux" or anything else), but admittedly I didn't focus to hard on it as I tried to cover as much as I could of the screens, buttons, questions on the list, etc. I understand the Leaf will be at Plug-in 2010 in San Jose at the end of this month, so I'll check again if I can. And if anyone's in the area, Tuesday the 27th is public night, so it would be fun to see any of you there! The PN panel will be comprised of me, Bill Nye the Science Guy, Martin Eberhard, and Jessie Deeter (our producer on WKtEC and ROTEC).
A side note on the sound...I saw Phil LeBeau's CNBC report that one of the issues of the car was a tinny motor whine. Unless it only comes in at high speed, I think it was in his own head. You can technically hear the motor, yes, but particularly with the insulation, it's quieter than nearly every other EV I've driven save maybe the Volt in EV mode. I can also confirm others' reports that the added noise is no big deal from within the car- forward sound is basically imperceptible, and reverse warning is noticeable but not as annoying as they generally are (didn't hear either one from outside the car). However, it in no way changes my general position on mandating added noise to these vehicles.