If you are only stopping through HK for 7 hours tomorrow I dont think there is any chance of picking up the iPhone 5 like other people have said. Even if you were here the whole day getting your hands on one this week might prove a bit difficult.
There will be massive ques at the Apple store and other authorised dealers.. the unauthorised ones will be marking the phones up by a couple hundred US$ just because they can, people will still buy.
I want an iPhone 5 but I am going to be patient until it's a little easier to get one.. until then, I have my fingers crossed for this free giveaway that I signed up for:
http://www.localiiz.com/giveaway