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A very limited selection, but then apple only carries a limited selection of cases. As time goes on, more and more cases become available.
 
Considering Apple made a custom case for the iPad, iPhone 4, and iPad 2 and they were available at launch, Apple will more than likely make an iPhone 5 case and it will be available on day 1.
 
When iPhone 4 was unveiled, Sena announced cases few days later and promised delivery around the time iPhone 4 launch date.

I was able to order one and they actually delivered it couple of days before the iPhone was available. I'm hoping they can do the same this time too.
 
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