I just got back from the dealer (South Bay Ford, in Hawthorne CA) and here's what they told me:
If you have an iPhone, iPod, or iPod touch with the latest iOS, and connect via the USB connector, the Sync system will eventually lock up. The system will have to be reset before anything else can be done. For us, that means pulling the fuse or disconnecting the negative battery terminal and waiting a few minutes. Ford, Apple and Microsoft are doing the finger-pointing do-si-do on this issue, so this square dance is going to last a while.
Once you've reset the system, older iPods with click wheels should work--the technician connected his iPod Classic and it worked like a charm. Streaming via Bluetooth should also work. (I haven't tried that yet; I'll let you know what happens.) I don't know about the Nano; I would assume it operates the same as the iPhone or iPod Touch.
Also, if you have a Flash drive formatted with FAT32, it should work after reset. I connected one and the system came right up.
I'll check out the Bluetooth tip at lunchtime today and I'll let you know what I find.
Hope this helps,
"He has eaten the pancake. He will never come back to us now."