I was at the Apple store today looking to buy an iPhone 4 dock. It was fairly busy (mostly around the iPhone 4). I happen to notice a small crowd (about 6 people) around in the back. People were crowding around someone who was trying to return their iPhone 4. As the Apple store employee was processing the return, people were questioning him why he was returning and he said it was because of the antenna issue. Someone offered him $400 cash for his iPhone 4. He declined. Another person was pissed because they would not let him buy the iPhone 4 that was just returned. He didn't mind paying the full upgrade price.