this is not the model coming to the U.S. because there is no LTE connectivity. Actually, the best way to determine which version of the Samsung Galaxy S III was involved with the FCC visit is to sneak a peek at the label. Sure enough, the label happens to read model number GT-I9300 which is the international model of the phone.
The device is about to be launched globally at the end of the month and the U.S. variant is coming in June. Besides the U.S., two other countries will be receiving the LTE enabled model later this summer, Japan and Korea.
source: FCC via Engadget