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I've heard every day. But I'm not sure. And havent heard first hand.

If it's like it was for iPad 1, it will be very sporadic, maybe once or twice a week depending on the size of the store. They'll usually get 5-10 of each size, but they won't always come at the same time. They aren't shipped our of Best Buy's distribution center (they come by private courier) so the workers will never know when they're going to come until they actually arrive.
 
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