Hi Marco,
I think that jbpm project will continue development of BPMN2 as soon as we are done with nearest release (4.4). Of course it won't be at the same pace as it would be with Joram but with small steps BPMN support will go on ;)
I agree with HuiSheng that it is not an easy job but I am sure we will make it.
I would like to suggest you to go through all BPMN related issues in jira and vote for those that are important for you. Well appreciated would be as well if you could provide as with a list of features need to be implemented and post it on the dev forum so we could prioritize togehter.
Let me know your opinion.
Cheers
Maciej