That's an interesting video, nothing ground breaking, nothing what I'd use right away but stuff that takes time to figure out from changelogs, docs and source neatly packed into a short talk, I really enjoyed that.
What feature is that? I won't be able to watch anything with sound for at least a couple of days and I'm curious. ^.^;
I'd add the phrase "type system" that was mentioned more then once near the end, so this is less impossible then it was before. As a more immediate consequence we might get a more useful dialyzer that works with Elixir AST