I would be sketchy about this because who knows if they are allowed to do this. Both AT&T and Apple are doing it on the 15th, so why would a store that has no connection to the phone get to do it early?
I would wait because what if something happens and these people do not get their phone because Radioshack messed up?! Then those people think they have iPhones and find out too late that they do not and can not get one in time for launch.
Just something to think about. 🙂