We've just shipped our first application whose core algorithm was written in Scala. Regrettably, the project didn't lend itself to "getting our feet wet," and it basically boiled down to the Scala modules being black boxes while the rest of us worked in more pedestrian technologies such as Java and JavaScript.
But the project was an overall success and Scala looks to be adopted in 2-3 other projects over the next half-year. So I've begun spending some of my copious spare time playing with Scala.
I'm not the world's biggest fan of the JVM, but that's the standard platform for our high-level applications and it looks like Scala is a good choice for type-safe concurrent programming on that platform.