What gives us the idea that this is the variant of the upcoming Android flagship for the nation's second largest carrier is the inclusion of LTE Band 17 on the device. In the states, this is used exclusively by AT&T. Also, the dimensions of the phone add up perfectly. And lastly, the UserAgent profile listed this model number as having a 1080p screen.
While a visit to the FCC doesn't mean that a U.S.launch is imminent, it is one task that can be crossed off on a carrier's "To-Do list" before a device is indeed released in the U.S. AT&T has already announced that it will start accepting pre-orders for the Samsung Galaxy S4 on April 16th for $249.99.
source: FCC via Engadget