Today, Oracle officially announced Oracle BPM Suite 11g. To my knowledge, Oracle BPM Suite 11g is the first and only executable BPMN 2.0-based BPMS available today. I've had a chance to try it out, and it is really impressive. The product provides a united runtime environment for both BPEL and native BPMN 2.0, uniting two previously distinct BPMS offerings.
I expected a minimal implementation of BPMN, but Oracle far surpassed those expectations. They support all the important event types - message, timer, error, signal - including boundary events (interrupting and non-interrupting) and event subprocesses, so they have really set a high bar for other vendors who will claim BPMN 2.0 support later this year. They also have great business rule and BAM integration, and a configurable end user mashup environment called Process Spaces that supports team collaboration and "social BPM." If you want to find out more, I wrote a white paper about it, which you can download here.