A new iPhone? Rumor had it that it hadn't gone into full scale production yet, but who knows how accurate that is.
It seems like camera parts and cases were already being leaked over the weekend.
Plus if it's really just a minor upgrade, to a 4S, instead of the iPhone 5, maybe a full scale formal announcement really isn't necessary. It can still run the current OS, until iOS 5 is formally announced in the next month.