Standard on all AMEX, at least the ones issued by AMEX not sure about the ones with partner banks. I know my USAA AMEX does it as well as my other AMEXI've bought launch day iPhones since 3G and none have had issues.*
*iPhone 5 had battery problems within a month. Turns out, they all have battery problems (READ: Crappy life not even close to specs).
Is that standard on all AMEX purchases or some sort of program you're on? I bought mine with AMEX, so was just curious.