But taking it seriously does not mean putting up with its limits. Yes, ES6 will finally give us a lot of things we've wanted for a long time, and node's streams are being standardized for the browser as well, but we shouldn't stop there. There are some interesting ideas we could explore with asynchronous code in StratifiedJS, maybe that will get us out of callback hell.
When talking about diversity in a development environment, transpiled non-js languages aren't in the top 3 things that come to mind, but yeah, sure, why not try Haskell in the browser, or even C++? Although to me it doesn't feel right to use non-native tools like this (could it be the scripter in me talking?), if we can create a new system where new learners especially can be shielded from such arcane knowledge as what a stack overflow is, among other things, we can use the browser as playground to experiment with new things. (Shriram Krishnamurthi's talk, while not the most immediately applicable to our work here, was definitely the most entertaining and motivating for me).
And React is something I'm really itching to try soon after this conference, even as I'm still not totally convinced about the spaghetti-soupish bits of HTML inside the Components.
On a final note, Prezi's new auditorium is an amazing venue, well with thought-out spaces and beautiful details everywhere (power plugs in the seats!) – but all this shouldn't be surprising from such a design-driven company.