A nice treat for Galaxy S III owners on US Cellular is dropping today. An update to version R530UVXAMD4 is going out via OTA soon, but you don't have to wait. US Cellular says you can pull the update manually from the Software Update menu. The full update can also be downloaded from Samsung and flashed to the device over USB.
This update is based on Android 4.1.2, so there's no surprise 4.2 update. Sorry, it's the same underlying version from the March update. There's still some neat stuff in the package, though. Here's the full changelog from US Cellular:
Smart Switch support enabled
Added multi-window feature
Contextual page, tag and menu
Multi-windows sounds like a great addition, and Smart Switch is also pretty handy.