I have not heard any discussion regarding the compatibility of our old accessory cables/docks with the iPhone 4. I remember that there was a charging issue with one of the versions (I think it was from the original to the 3g). Has there been any confirmation or discussion about this issue? Aside from the actual physical design that could be remedied for my existing docks with new dock adapters, I am wondering if there will be any issues with cables/charging/back-up batteries, etc. As another related matter, my 3g connects to my car's stereo beautifully. I wonder if either the new phone, or iOS 4 will change this. As I am still running 3.1.2, I cannot test this myself yet.