Today I talked with a samsung agent from Samsung France with live chat!
I asked him about KitKat update for the Galaxy S3 4G GT-I9305! He said currenlty Samsung is developping the firmware for The S III 4G and It will be announced when It s done! But unfortuently he doesnt know when it will be availble to download because Samsung has plenty of phones !
So Surely Samsung will update the S III 4G to KitKat