Alpine has updated it's FAQ: http://www.alpine-usa.com/support/faq/441
Alpine conducted a quick compatibility test with the iPhone 5 and found that certain AV, AVN and Digital Media Receiver products are not able to playback iPhone music over the USB connection. Customers can, however, continue to listen to music from Pandora, or access their iPhone's music library wirelessly via BluetoothA? Wireless Technology.*
In addition, it has been reported that Bluetooth streaming meta data and control is no longer functional with iOS 6. We are working to verify all models affected.
Alpine′s engineering teams have begun detailed evaluation and specification confirmation and we will provide updated information as soon as investigations are finalized. Compatibility with other Alpine products is being verified and will also be confirmed later.
As of 9/21/2012, Alpine products verified not compatible with the iPhone 5 are:
Issue: No iPod / iPhone Music over USB
Models Effected: INE-S920HD, INE-Z928HD, IVE-W535, iDAX305S, iDA-X305, iDA-X100, and iDA-X001
We will continue to update you regarding compatibility