I've started learning the language Scala and the web framework built with it, Lift. I'll be making some blog posts soon on these.
I'm going to hold off on making any final judgments until I've written some real things in both. But so far I'm really liking Scala and Lift. If you haven't looked in to them, I would recommend you at least give Scala a quick look over. Even if you don't ever intend to use it for your main web app, it can be great for back end processing jobs, as concurrency is built in to the language. And, if like me you work on some projects that can only be distributed to customer's systems that only run the JVM, Scala is built right on top of Java. Sometimes JRuby will allow you to distribute on to the JVM, but you don't always get the newest and best running JRuby.