While there are strides of devices moving towards the Kit Kat kingdom, there are still a glaring number of OEMs that have yet to update some of their older, yet still capable, devices to Android 4.4+, with Samsung being one of those manufacturers. We have had various leaks displaying which devices should be getting the update to the newest build versions of Android this year, and Samsung has even stated to some degree that the updates would be coming, we just didn't have a confirmation on when.
This internal document said to be officially from Samsung that was just leaked today though gives us a little more insight on when some of those older devices from last year and before can expect to see Kit Kat running on there devices. You might be surprised to know that the Galaxy S III international model(GT-I9300) is having some issues, which basically leads to the build being cancelled for the device at this time. For now we might as well just consider it being put on hold indefinitely until Samsung can get things working properly, but we can't rule out the possibility that it may never be updated to Kit Kat due to unresolved issues(although it's rumored that the problem might be due to the 1GB of RAM compared to the U.S. LTE models 2GB)as Samsung is putting it. The internal document list isn't all about the Galaxy S III though, there is a number of other devices that are listed that seem to be right on track to get their updates with some being sooner than we think. Keep in mind though these are just general windows of time and not exact days. Even with the Galaxy S III International model having some final testing that needs to be done before things continue moving along, the list is comprised of "confirmed" devices.
Among the list we can see that the Galaxy S III LTE model is confirmed and in final testing for the Kit Kat upgrade, as well as Galaxy Note 2. Both those devices are scheduled to see their updates begin to hit devices in May and April respectively. It should go without saying these updates are incremental, and some devices may have begun to get them while other haven't quite yet. You can also see the updates coming for the Galaxy Note 3 Neo and the Galaxy S4 mini and S4 mini LTE. For the confirmed devices on the list, the update ETAs reach out through June of this year, so it might be safe to say that all those listed could have Kit Kat by Summer's end.