A new release of java-gnome was released on September 26th. As you can see in the release NEWS file the major improvements with this latest version is improved documentation, an increased API coverage and internal refactoring. In particular there has been an increase in the coverage of the Menus, Toolbars and Actions. Preliminary coverage of some container related GTK widgets have also been added.
It appears that the java-gnome project is really staring to ramp up and catch some steam. Hopefully we will soon see full API coverage.