My local Radioshack was a mess at pre-ordering my iPhone, and with the fact of I being the only one who has been asking them their process about the iPhone 4, they had to always look at their printed paper which included the instructions to follow for the iPhone 4 release. In the end, they didn't let me because the way I was going to get it wasn't by neither upgrade or adding a new line, you see, on May 27th, I got my 16GB 3GS, I did it to keep the unlimited data plan. So, they were like indirectly saying that I wouldn't get the phone on launch day because of the pre-orders, I told them to not worry, there will be probably none other than me that day at 5:30AM at the mall entrance, even though they insist that they would be opening at 9AM (current opening hour).
So yeah, he did guaranteed that the phone IS going to be available on their store on launch day and I respond to him that I WILL get one 🙂