Buy iPhone 5 unlocked in US Apple Store?

I'm traveling to the states on the 22nd of september. I was wondering if it's possible to buy an iPhone 5 unlocked directly in the apple store. Just checked the Apple Webshop and it's possible to get a 4s without contract. So I think they also will sell the iPhone 5 unlocked.

Other question is the availability. The iPhone 5 will be shipped at the 21st of september so I guess at this date they also will have it in stores. Does anybody of you have any experience about it from prior iPhone releases? Do you think they will have it in stock for a few days?

You can buy one without a contract that doesn't mean it's unlocked apple don't sell unlocked phones or any products it probably will be hard to get for a week or 2 since its a newly designed iPhone unlike the 4 and 4s didn't have many differences