Apple might have it right for car audio
Besides the speakers, another place where I think the IPod with dock blazed a trail with the dock connector was for in-car entertainment connectivity. You could get a box to connect your iPod to the head unit and be controlled remotely, pretneding to be an OEM CD changer. With Android not having a common dock, there is no chance of any box to wire in your phone to the stereo. Of course bluetooth is all well and good for calls, but you need a seperate charger or run down your battery even more when driving and listening to music using it.
Where the new dock might succeed is that it has digital audio output (presumably on the S/PDIF standard), which is great - car head units have this (mine requires conversion from analogue of iPod to S/PDIF). However the control and data over serial is useful for this purpose, so if that's been dropped in favour of USB then any car audio converter isn't going to get easier to build.