FWIW, the Corning site says the "Galaxy S II" has Gorilla glass. Doesn't specifically call out the US variations. Also, there's a "semi-official" post from a Sprint rep saying it is Gorilla glass here:
I foolishly started a new thread for the same topic and I am sorry about that. I also have a scratch and cant figure out how the scratch was even made. I don't have insurance and I guess I am stuck with a phone with the scratch even though I was meticulous about babying my phone. This fully sucks. I wish I could just swap it one for one like tmobile allows.
[Confirmed] Epic 4G Touch DOES have gorilla glass - xda-developers
No scratches on mine yet, but I don't put it in the pocket with keys/coins.