Starting with Ubuntu 11.04 (codenamed Natty Narwhal), Unity would be the default shell of choice for the desktop edition. Though Unity (already available on the netbook editions) is far from ready, there are a couple of cool features it brings to the table.
The immediate changes are aimed at reducing the wastage of screen space. The application menu (in the maximized mode) gets integrated into the top panel. So does the status bar - this would be replaced by an indicator on the top panel. This is a huge relief for people like me who runs firefox with extensions that hide menubars, trying to salvage every bit of screen space.
There is also the promise of a Mac styled dock and application switcher.
The Unity project plans to include zeitgeist, a sophisticated data engine that understands user activities and correlates them. This can provide useful context to search and browsing applications.
There are also plans to evolve from directory based file storage to something that’s more intuitive and search oriented (yey!! first step towards tag based systems).
GNOME 3 is coming next April, and there is a worry that throwing in a new desktop shell would divide the development community. Nevertheless I like Ubuntu’s aggressiveness when it comes to redefining the image of Linux.
In the good spirit of choice, GNOME and KDE would be very much available as login options.