I got the phone that I order on 7/31 on 8/13 while traveling to Hong Kong (the phone was shipped to a friend's place in Hong Kong), but using the iphone 4 case App, I was able to use an US iTune account and have the case delivered to my US address. (I live in US.)
So to me, even though I purchased the iPhone 4 in Hong Kong, the case does not necessarily have to be shipped to a Hong Kong address.