It would be great to provide a collection of service/classification rules for widely-used services. For example for service/software created by Mircosoft, VMware, for VoIP phones from different vendors etc.
Maybe some people are willing to share there self created services (pmd files) and make it accessible for use by other community members.
I think the Extreme engineers have a collection in there labs, too. A collection of services definitions could save many people a lot of time.