Unfortunately, the tech ninja who supplied this image decided to have a little bit of Photoshop fun with the device, by pixellating the user interface so that there is nothing much which can be inferred apart from the number of columns. Chances are it was running on a stock version of Android 4.0 Ice Cream Sandwich, but knowing Samsung, their final, polished product will in all probability be accompanied by their very own TouchWiz UI!
It does seem to resemble the Galaxy S2, albeit with a far more rectangular home button, not to mention the front facing camera being located on the top right and corner instead of the opposite position in the Galaxy S2. What do you think?