A beta of the forthcoming SWT Designer v7.0 is now available for Windows, Linux & OSX.
This release includes full support for UI Factories.
This should be installed into a clean copy of Eclipse 3.4 that does not have any earlier version of SWT Designer (e.g., v6.9.0) installed.
Updated preliminary docs are available here.
All bug reports should be sent to email@example.com.