So, I generally have two classes of scripting needs: systemy/unixy stuff and systemy/application stuff. Most of the applications I work with in $dayjob are Java. Over the last year or two that means I use Ruby (MRI or JRuby) as the case may be. Tonight, prodded by the new book I broke out Scala for doing a bunch of in-REPL statistics crunching using the wonderful commons-math library.
I love it. Don't know if I love it enough to replace JRuby for typical Java-interaction hackery, but enough that I am going to switch back and forth for a while so I can decide.
Hadn't actually used scala in a few years, so is great to break it out again!