This is an easy one to implement I think.

First, read:

http://www.rhq-project.org/display/RHQ/Plugins+-+Snmptrapd

Notice that the plugin jar has MibTrans.properties embedded in it that contains the maps of oids:

"The plugin currently has no mib parser, so the generated event payload is passed as 'oid: value' into the events.
It is possible though to define a manual mapping. There is a file MibTrans.properties within the plugin, that maps oids to names"

There is no need to have this extra .properties file because we can use the plugin configuration to store that mapping.

this would allow us to:

a) create the mapping in the GUI
b) update the mapping in the GUI without cracking open the existing jar and updating it and then pushing out the entire plugin jar to all agents so the new update it found
c) perform group configuration across multiple snmptrapd resources

What we need to do is:

1) remove the MibTrans.properties file from the jar file completely - totally delete it
2) create a simple list-of-map property in the <plugin-configuration> metadata of the plugin. The map has two simple properties - one for oid and one for name - we can even have the oid property be forced to validate against a regex to make sure the user enters a valid oid
3) have the plugin component no longer read the .properties file but instead get the mappings from the plugin configuration.

This should only be an hour or two worth of work.