Yes, I added ability to open bpmn2 processes in Guvnor standalone editor.
To use the standalone editor in your application, you can use following URL for example in a div or iFrame or just in a window (Guvnor has to be running, for this example on localhost:8080):
http://localhost:8080/drools-guvnor/org.drools.guvnor.Guvnor/standaloneEditorServlet?packageName=defaultPackage&categoryName=mycategory&createNewAsset=true&assetName=myprocess&assetFormat=bpmn2&client=oryx
This will create a new bpmn2 process named "myprocess" in package "defaultPackage" with category "mycategory" (note has to previously exist in Guvnor).
To open this process later on with standalone editor, you can use
http://localhost:8080/drools-guvnor/org.drools.guvnor.Guvnor/standaloneEditorServlet?assetsUUIDs=XYZ&client=oryx
where XYZ is the "myprocess" UUID that Guvnor generated.
You can see the standalone editor can also be used within Guvnor itself: http://people.redhat.com/tsurdilo/vid/gatewayexample.swf
I will add a blog on this soon.