I'm in Canada and had my JB iPhone 4 replaced at an Apple Retail store. I restored phone as new in iTunes prior to going to the store. I even added some apps so the phone wouldn't appear so new. I was informed that it was store policy that the iPhone be scanned prior to giving me a replacement. Didn't do that when I had my iPhone 3GS replaced 4 months ago
Perhaps Apple is scanning to determine if the phone is Jail Broken? The Apple employee plugged in the dock cable into my old phone and was checking the info on a store iPhone. The replacement iPhone 4 is a refurb.