Samsung or AT&T never mentioned anything about the update is 4.3. in fact all the other variant outside of north america had updates rolled out several weeks ahead and was 4.2.2. North American carriers were just late than others. I don't believer we will ever receive 4.3 updates since I've heard a rumor (just google it) that android 5 will be rolled out towards end of this year, and I have a strong feeling s4 will skip 4.3 and go straight to 5.0+. either way, we are getting some updates.