Samsung released Android Kitkat 4.4.2 for the Samsung Galaxy S4 Gt – I9500 variant. The ROM is available for Russia. It is also mentioned that Samsung is rolling out the lastest Android 4.4.2 for Indian GT- I9500 users also. So If you are from India or Russia check for the availability of latest firmware for your device (Settings > More > About Device > Software update > Update.).
Here is the details from Sammobile
Model name: Galaxy S 4
Version: Android 4.4.2
Build date: Thu, 13 Feb 2014 11:33:19 +0000
Product Code: SER
If you are interested you can get it from here with instructions on How to install it.(Remember it is Russian)
If you are not from any of the above countries and if you have a rooted Phone, and aware of flashing, Wanam have created a custom ROM based on the XXUFNB3 ROM here, you may flash it if you want. I flashed it yesterday on my 4.3 ROM and it worked well.
If you are flashing it Remember We have tested it on our Samsung Galaxy S4 I9500, but
Flash it at your own Risk
We don't take any responsibility for any Damage
Do not Flash it on other variants of S4 like 9505