A dedicated digital audio jack would be a useful addition, it could even take the place of the useless composite video RCA, so the port arrangement of the Model B would be kept.
With a digital audio jack a pi could be a decent hifi music streamer, better and cheaper than the AirPort Express. Now you need a $30-50 splitter (or the hifiberry add on) to get the audio off the hdmi, which makes the total cost more than double.