First post! Hey all!
I also ordered an iPhone 5, and have MINI Connected. The best case scenario is this: Until mid-October you'll have to stream your music via bluetooth or aux. When the converter adaptors start arriving, you'll be able to use everything but videos and the Apple-Designed iPod Out interface. You can still see the album art, charge, etc.
I would be surprised if BMW/MINI didn't have an updated cable for us by mid-fall. Remember, all the 2013s are beginning to roll out. As far as I know, BMW iDrive and MINI Connected essentially use the same I/O hardware, and I know they will make sure the new cable/snap-in adapters are updated by then. Losing attachment sales because your iPhone is too new doesn't sound very "BMW" to me.
Lightning isn't going anywhere. All automakers are forced to upgrade. It's just a matter of time (and frustration).