I've lost track of how many Galaxy S3 leaks we've seen so far. This is another one, and so far the most "realistic" one, too, because it looks like a photo of an actual device, rather than just a render of a device. From the looks of it the phone seems to be made of metal - just one piece. And it looks to be very solid, and probably feels just as solid in hand.
In the front we can see it still has a home button, which according to the rumors it's something the Galaxy S3 will have. They must think of it of some sort of branding, but I think it's a mistake, for the same reason it was a mistake for the HTC One X to have physical buttons.
First of all they don't make sense anymore. Software buttons make for a more integrated touch experience, and second, until the menu button is completely deprecated (so until all apps adopt the ICS styling), we'll still see an extra bar at the bottom that will show us a software menu button.
But the real question is, is this even real? Chances are it isn't, so don't get your hopes up (or down) yet. Samsung has done an excellent job so far keeping the device and its specs very secret (most of the rumors were just speculation), and we've heard they even walk around with the device in a secured briefcase and bodyguards whenever they want to show it to some carrier's representatives. We haven't see this kind of secrecy at anyone else except for Apple.
So far this strategy has paid off for Samsung, because the amount of hype for this device is huge, and I bet they will sell even more units than in 2011, especially if they do a more unified launch (no 4-5 months delays for US), and the devices still manages to impress after all the hype.