If you don't pay close attention, you may not even notice it, but Samsung sneaked a preview of an American Galaxy S II variant into a promo video it released earlier today. For the entire clip you stare at the version we're all familiar with, which sports a large home button on the bottom. Then, at the very end, a slightly rounder handset with four capacitive buttons and no large home key pops up on the screen. It looks a bit like the T-Mobile-bound Hercules, but not quite as curvy around the edges. It could be Sprint's Epic 4G Touch or perhaps an as yet unseen model destined for AT&T or Verizon. Check out the full promo video after the break.