Samsung is sending out updates to fix a vulnerability that can be exploited in some Samsung Exynos processors discovered in December. If you receive a notice of the update be sure to download it and install it. AT&T has also confirmed that its Jelly Bean update for the Samsung Galaxy S III is out over-the-air (OTA) via Wi-Fi only (video and update directions follow).
Don't forget it is always a good idea to backup your data before and update as well as have your phone fully or at least 50% charged during the update. We also learned a new "don't try this at home."
Here's the update schedule so far for security updates: