Since JS is not just limited to the web, there's a bunch of other fields to explore. Not all are for finding new jobs, but knowing them could add sugar to your portfolio.
- Robotics, there's the Tessel.
- If you're into type-hinted JS, then there's TypeScript.
- Embedding JS in a microcontroller, there's MuJS.
- Programming on mobile, there's PhoneGap.
- Taking that further, where JS is your phone's platform, there's FirefoxOS.
- Into game development, there's a lot of game engines for JS.
- Desktop app development, there's NW.js