Samsung already added support for KitKat to Galaxy S4 Google Play edition devices. Google already confirmed the news and planning for a rollout soon.
If you have one of the Galaxy S4 Google Play edition smartphone you will get an update notification in next few hours if you have not received one already.
Android KitKat does not bring much changes to look and feel but it added many performance enhancements and also improved the multitasking.
Samsung also released source code for Galaxy S4 KitKat. You can download the source code from here.
