Right, the idea is to transition newer JVM languages in. A lot of legacy code would be in Java, so the Scala or Clojure interop would let them build on top of all that. Maybe start with a more or less self-contained component, like a web services API or something could demonstrate the advantages of developing with newer languages.
At least, that's been my experience in places that lure with something glamorous and then do only a very small amount of it.