This is a nice story about how a developer sold management on a Scala solution, put it in production, and handed off the maintenance to other developers.
For All You Know, It's Just Another Java Library
When you wanted to follow the advice of the Pragmatic Programmers and learn a language every year, you had to do it at home. You couldn't bring your new learning language into work.
Today it's a different. You can learn dozens of different languages and run them on top of the JVM or MS' CLR.
Also, if you're going to learn a new language, make sure it's hard enough to hurt. If you know Java, pick something very different, like Erlang or Scala. Learn to think in a new way.