Did you add a line or just upgrade?
Just an upgrade.
I had the original iPhone and my wife had a pink razor. She wanted my iPhone so I told her she could have it and I will get the 3G. she was cool with it. so I went in and upgraded to the new 3G, and put her phone number on the old phone and my number on the new on.
The AT&T store didn't ask me one question because I had the AT&T rep I called put everything in the notes so there would not be an issue.