Ladies and gentlemen, we have our first Android 4.1 leak for an existing phone. Following the appearance of a blurry-cam video of the ROM yesterday, a pre-release Jelly Bean firmware for the international Galaxy S III (Galaxy S3, GT-i9300) has leaked out online over at SamFirmware. The ROM is based upon Android 4.1.1, carries the build name I9300XXDLG4, and was built a couple of weeks ago on July 31. It's a test ROM that's not of release quality, so expect crashes and bugs if you decide to install this one.
On the surface, the Galaxy S3 running this leaked firmware is still a Galaxy S3, and the TouchWiz Nature UX is still the UI you'll see most of the time. However, new Jelly Bean features like Google Now and the redesigned notification area are present in this build. The latter is a little janky in the leaked ROM -- location services don't seem to be working, but the voice-activated Google Search was fully functional, and fast as ever.
Performance-wise, the leaked Jelly Bean ROM doesn't offer huge performance boosts over ICS, but the S3 was a beast even on Android 4.0, so we'd argue there isn't much room for improvement in this area anyway. The Jelly Bean-specific launcher enhancements weren't shown in the this ROM -- for example, you're not able to make widgets resize to fit into a certain space, or nudge icons out of the way. We're not sure whether Samsung will include this in its final Jelly Bean firmware, as it likes to do its own thing in the TouchWiz launcher anyway.
Finally, NFC support was enabled in this build, though the phone became a bit confused when trying to transfer files to and from other Jelly Bean devices -- essentially, it would try to use S Beam even when the other device didn't support it. Again, not surprising for a leaked pre-release ROM, and something we full expect to be sorted before the final Jelly Bean update hits.
Check out our hands-on video above, or, if you're feeling brave, you can find instructions for flashing the ROM itself on your international (not U.S.) Galaxy S3 at the source link below. We've also got a couple more screenshots after the break.