I'm planning on going old school and re-learning C and Assembly for x86 and, in particular, ARM architectures. My reason for doing is that I want to get back into embedded systems.

I also plan on picking up Rust and somehow integrating it into my workflow (I'm a web developer).

Ideally, for the future (2015 and beyond), I want a basket of languages I could use for building web-scale applications. So, for example, within a single application:

  * Erlang -- distributed messaging
  * Rust -- heavy lifting for various tasks
  * Python -- various data munging tasks and rapid development
  * Javascript -- client side applications (e.g. Ember.js)
  * C -- in those rare cases where it would be needed

I think I would stick with these languages for the next ~10 years and try not be distracted by anything else.