GNOME 3, due for release in April 2011, is going to be revolutionary. The Desktop is designed to reduce distraction and interruption and to put the user in control. Messaging has been seamlessly integrated into the desktop. An improved file manager, redesigned work spaces, and better accessibility are some of the notable improvements.
The GNOME Project has published a new website Gnome3.org showcasing the GNOME 3 Desktop environment.
If you are really interested in trying out GNOME 3 just now,you can do so by compiling it yourself using GNOME's JHBuild sandboxing tool.