Ask HN: Best new language/framework to learn with commercial prospects?

I've been in enterprisey Java-land too long. It's hard to compete with Python/Ruby programmers with N years commercial work experience (where usually N > 1). I had the idea that I could learn some new exciting programming language or framework that is still being invented, so I can get in on the ground floor, so to speak. For example, like asm.js.

Background: I have been made redundant, but I have a few weeks financial cushion, and I want to avoid just falling into yet another job like the ones I've had (knowing that people in the local market would probably gladly pay me well to carry on doing the same sort of work).