Thanks for the feedback guys, lots of food for thought there.
the marketplace for Ruby or Scala skills is negligible compare to Java or (for example) C#, so why bother!?
Not exactly true. A lot of studios and companies use Ruby or Python for backend development.
Not to mention that some of us just happen to love programming and don't view everything through the lens of what will make us the most efficient cog in a corporate machine.
Very true, don't get me wrong I'm a developer at heart and love the challenge and creativity of programming, I was showing my cynical side when I said that I had no desire to learn a new programming language
For reference http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
is handy to keep tabs on language popularity (from a potential job perspective).
I'm actually quite enthused about this objective now, if anyone's interested I'm thinking of giving Ruby or Ruby on Rails a go:
* it's an OO language, so it will be interesting to compare and contrast with Java as I port my 3D software.
* as a couple of posters mentioned it's often used in the back-end (we actually do use it in my organisation, just not in any of the areas I've been involved in as yet).