I want to use BPMN in WSO2 ESB, but unfortunately it seems that WSO2 ESB does not support BPMN and only support BPEL. Is there any way to integrate a BPMN engine such as activiti or jBPM or something else with WSO2 ESB?
You might want to look at Intalio|bpms. It is creating a valid bpel process from a BPMN diagram.