They use AJAX patterns heavily and leverage the browser XML namespace support.
Shoping - New way to shop
Portal - A new way to do responsive Portlets based U/I
Google : Totally new way to experience search using Google API and using drag & drop to bookmark
- Defining the layout (panels, windows and decks)
- Styling the interface (themes and skins)
- Creating user interface controls (menus, tabs, trees, sliders, etc.)
- Adding behaviors (display, hide, loading data, animations, etc.)
- Including form functionality (conditional forms, input validation)
Extending the namespace support to clean up the page layout code seems to be in vogue. Another project Novell Xforms is a cute project leveraging that for xform implementation.
Years ago I was part of the team that did the Xform 1.0 implementation that we contributed to IBM Alphaworks site It formed the basis for some of the IBM products that are coming out with revised implementation. Given a second chance we would love to go back and redo it using namespaces and not IE Mime handler.