The latest update of syslog IETF draft "The syslog Protocol draft-ietf-syslog-protocol-23" (here) enlightens its readers that it now has "structured data elements, which can be used to transmit easily parseable, structured information and allows for vendor extensions." Wow, amazing!
Have you ever seen a syslog entry that had "enterpriseId", "software", "swVersion" or something of that sort?
Why not? :-)