FYI, leak surfaced today. Samsung is readying the S4 features for the S3. Coming to a rooted device soon near you.
All the 4.2 S4 features. Its incomplete so its still up in the air if the camera features are going to be included.
Tabbed settings and other visuals from S4 included.
There was like an app drawer or something that showed up, like a task manager or app switcher that allowed you to see all the things you had running. Had a tab on the left side of the screen to pull it out. Also noticed all sorts of new tips, etc when I went into apps, etc. Those all have since disappeared (and I know I didn't check that "don't show this again" box on some of them).