According to BGR, AT&T's version of the Galaxy S II have the model designation of the SGH-i927. Just as interesting is the fact that the device will sport a four-row slide-out QWERTY keyboard.
The Galaxy S II is already the fastest-selling Samsung smartphone of all time, even without a U.S. carrier. In the rest of the world, however, the device has been keyboard-less in the rest of the world. It could be that AT&T and Samsung see the hardware keyboard as a good way to attract users away from the iPhone.
While AT&T still sells --- and always will sell --- a massive number of iPhones, there are some people who will never buy it, simply because it does not have a hardware keyboard. Combined with Samsung’s 1.2 GHz dual-core processor, 4.3-inch Super AMOLED Plus display, and overseas benchmarks showing the device blowing away other Android smartphones, the hardware keyboard might be a key selling point.
It's unclear if Galaxy S II variants on other U.S. carriers will also support a hardware keyboard. The Galaxy S was sold only with a keyboard on one carrier: Sprint, as the Epic 4G.
Interestingly, from the image obtained by BGR above, the four-row keypad has two tall, thin buttons on the left and right side that duplicate the functionality of the four capacitive touch buttons always seen on Android phones which support Home, Menu, Back, and Search functions. It's the first time we've seen such a feature.
At the same time, however, the keyboard is unusual in that the rows go straight up and down from row to row. Usually, there's some canting to a keyboard, such that it more closely resembled a PC keyboard.
AT&T's Galaxy S II variant was previously outed as the Attain (which may or may not still be the released name), but it's unclear if that will still be the shipped name for the device. Also noted in that earlier leak were the names of the Sprint and Verizon versions: Within and Function respectively.
Information still missing from these leaks: price and release date. Rumors have pointed to an August release in the U.S., however.