I made the open source project Babel and will be presenting on how JavaScript transformation and ES6 can help improve developer workflow and how it can futureproof their code. Not only transpilation to ES6 but how Babel has support for Flow, JSX and React so it can be integrated into many workflows extremely nicely. There are many challenges associated with transforming JavaScript as well as AST manipulation that I think would be extremely beneficial for the average developer to know about. There's even crazy stuff like transpiling proxies/Object.observe which wraps every single expression in a method.