Alpine just posted the following on their Facebook page;
We would like to announce that the highly anticipated Bluetooth firmware update for Alpine decks CDE-133BT, CDE-135BT, CDE-136BT, CDE-HD137BT, CDE-HD138BT, CDE-W235BT and IVE-W530 being used with an Apple iOS 6 (and later) device has arrived. This update enables Bluetooth audio streaming control and song information display with Apple iOS 6 and later. If you need this update, please click the link below to download and carefully read the instructions. If you have any questions, please call our tech support team at (800) ALPINE-1.
To download this update: http://alpine-usa.com/feeds/promo/13hubtupdate
I'm using the CDE-133BT myself but I haven't tried this since I live in Europe and it seems this update is only for USA at this point. If anyone from outside the USA has tried to apply (or succesfully applied) this update already, please post about it here!