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.).
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.