BPMN is a standardized graphical notation for drawing business processes. The standard has seen considerable traction in the BPM industry. Several pure play vendors have now BPMN representations supported out of the box in the modeling tool. Evidently, the first version of the spec wants to standardize the business process modeling notation. The spec very wisely provides a direct mapping to BPEL for execution. This further adds in favor of close tie up between business processes modeling and loosely coupled IT infrastructure.
The BPD modeled using BPMN can be easily realized as a BPEL process. The BPEL process may not be syntactically complete but has all the semantic elements correctly captured. The business definition of the process is captured with sanctity and transparently provided to IT as a blueprint for implementation.