Galaxy S3 buyers, and there are over 20 million of them already, know that Samsung promised during its IFA 2012 Unpacked event in Germany last week that its flagship devices will soon get updated to Android 4.1 Jelly Bean. The list includes the Galaxy S3, Galaxy Note 10.1 and Galaxy Note, although we expect other older Samsung handsets and tablets to also make the jump to the new OS in the future.

When it comes to the Galaxy S3, we have seen a variety of Jelly Bean leaks recently, which allowed anyone that was interested in running the latest Android version on their newly purchased device to install a pre-release Android 4.1 ROM. But most of those leaks were available only for the international Galaxy S3 version, with just one of them compatible with a U.S. Galaxy S3 model, T-Mobile’s.

Today, Sam Mobile reports that there’s a second Jelly Bean build available for T-Mobile’s Galaxy S3 SGH-T999 version, which can be installed over-the-air, via KIES or ODIN.

Obviously, we don’t encourage you to pursue such unofficial ventures and instead wait for the real thing to come out. In fact, it seems that the publication has an idea of when to expect the updates to roll out:

The first Jelly Bean updates will roll out next week.
The American Galaxy S III will get Jelly Bean by the end of this month.

We’ll be back with more details on the Galaxy S3 Jelly Bean updates in the near future, in the mean time let us know whether you’re running any of these leaked Android 4.1 firmwares on your device in the comments section below.