I haven't really checked out the lines at the apple store but a friend of mine who runs one of the AT&T stores in my area could not believe how busy they were on the first two days of the iPhone 4S going on sale. She said that it was busier than last year when the iPhone 4 was released. The bulk of the sales were upgrades from previous iPhones. I'm curious if sales will remain strong or it will taper off a lot once everyone upgrades.
