So far (what I've seen), there is a personalize option for the start screen, a new way to personalize it. Uhm, you have the swipe up feature to show all apps, 2 windows of Internet Explorer can be snapped now. You can snap 2 apps equally, not one bigger than the other. A start button is added, a resize tile option is added. Internet Explorer 11 is much smoother and faster than IE10 IMO. In Windows 8.1 Preview you have 1 animated start screen background, while in the final build you will have multiple others... The Windows Store was completely remade, you will see that a calculator metro app is included now, as well as Alarms, Reading list, Health & Fitness, Help & Tips, Scan, Sound Recorder & PC settings shortcut. Xbox Music has been remade as well. Long story short, you have a performance improvement, much faster & smoother on my laptop. New features & apps..