Hi Michael,
My opinion, save the org.jbpm.internal.log package has benefit for the jbpm framework, whatever the commons-logging or log4j or slf4j changed, we need change too much for the component in jbpm framework.
The only weekness is the logger cannot reflect the real invoking location, e. g, if we want to print the method or the line of the real logging location, it will always the org.jbpm.internal.log.Log. But I think this is not a fatal problem. Event the log4j or slf4j didn't suggest to print method/line number in appender.
So I want to save the abstract layer of jbpm - org.jbpm.internal.log package, and just close the JBPM-1211 and jBPM-2422.