In addition to new internals, the Samsung Galaxy S III features an all-new version of TouchWiz. So far, Samsung hasn't branded it with a number (admittedly, I've been calling it TouchWiz 5 all day despite that), but it offers a ton of new improvements as a result of Ice Cream Sandwich running in the background. Widgets receive a dedicated spot, messaging has received some improvements, and the app structure is different, just to name a few.