I've been thinking about querying the DB, but that seems like a last resort, I want to use the APIs as much as possible.
I checked the vCloud Programming guide and it looks like I can query the API using a packaged query like API-URL/vms/query or the entity resolver (Page 237 in http://www.vmware.com/pdf/vcd_15_api_guide.pdf).
Since i get the VM id in the MQ message, i can pick up the additional data using the API as i parse the message, i hope.