All work is now going on at https://git.eclipse.org/c/bpmn2-modeler/org.eclipse.bpmn2-modeler.git/
https://github.com/imeikas/BPMN2-Editor-for-Eclipse/blob/master/README - installation instructions and how to run from the source!
http://kverlaen.blogspot.com/2011/02/new-bpmn-20-eclipse-editor.html quick intro blog post.
UPDATE SITE URL: http://codehoop.com/bpmn2/
Most if not all of the stencils are supported. Full list is found in Supported stencils.
Elements and attributes enablement can be configured at the project level (BPMN2 category at the Project preferences). Property page contains all the elements that BPMN2 editor will support.
Properties editor now supports properties with simple data types (string, boolean and integer). Advanced properties need special handling so these must be handwritten. Created a sample for ioSpecification. Also editor supports jBPM5 specific attributes, they are located under jBPM tab. Please note that properties editor is not finished yet so you can't see the effect of disabling attributes. Disabling elements works.
BPMN2 Project Preferences
Simple properties View
For a full list of ideas for the future look at Future roadmap