Samsung has begun rolling out the Android 4.4.2 update to the Korean variant of the Galaxy S4, the one that comes with LTE-A connectivity. The update is currently rolling out to two variants of the devices, the ones with model numbers SHV-E330S and SHV-E330K, which are SK Telecom and KT's variants of the device. The update is now live on Kies, but we're unsure if an over-the-air version is available at the moment, though it likely will be in a matter of hours. This also bodes well for the international model of the Galaxy S4, which will (hopefully) start getting the update before we enter the third month of the year.
Coming back to the KitKat update for the Korean model, it should include the usual changes and features the newest version of the OS brings, such as white status bar icons, increased performance (at least in benchmarks), inbuilt wireless printing support, ability to easily select the default launcher and messaging apps from the settings menu, a camera shortcut on the homescreen, improved Samsung keyboard, and reduced memory usage.
You can check if the update is available for you by firing up Kies, or through the Settings » General » About device » Software update menu. If you have the SHV-E330S model, you can grab the firmware from our firmware section and flash it manually, though naturally this is only for those who are comfortable with taking the advanced route of not depending on the official upgrade method.