As someone who currently works on the Clojure lib for OpenNLP, I would like to throw in my support for a push to a more functional style codebase. Immutable objects and less global state would definitely make it easier to work with, be it with a Java refactoring and/or a move to Scala.
+1 for Scala/Refactor (or Clojure, but Scala is probably an easier transition to make :) - Lee Hinman
