The build number is showing as i9300XADLG4 and does show Android 4.1.1 and the OS version. The whole video doesn’t go into too much detail, but one can see the Jelly bean injections in the notification bar and Google Now. The S III glides through ICS with ease so one might not see to huge of a difference in video on the speed of Jelly Bean and Project Butter. It looks like it might be almost ready to send out to the world, when each variant of the S III gets the update will be a completely different story though. Hopefully with the speed at which Samsung was able to deliver the device across the globe, they will be pre-emptive in the update release and get as many carrier builds ready to go as possible when it is announced.
For now, you can check out the video below. Unless you speak Spanish though, you might want to turn the volume down.