As we saw with the Windows 8 welcome screen, Microsoft is taking cues from its mobile OS Windows Phone 7 in the design of its next big desktop OS.
WinSuperSite now has some images showing a new Internet Explorer-powered UI mode that is being referred to as "Immersive." A big clue to what the Immersive UI will be like is Internet Explorer, which takes on a look that's much like the IE Mobile browser in Windows Phone.
The Internet Explorer Immersive mode in current builds is locked to a view that is at 640x480, indicating its not-yet-finished state. It's likely that this UI and browsing mode is meant for touch-based form factors, such as a tablet.
The browser software works, and has features such as browser history implemented and executed in ways very similar to Windows Phone 7.