In his second dotJS talk, Addy presents Polymer, a new way of using web components to build apps.
Front End Web Security is hard. This talk goes through why there's no hope of patching every hole and suggests the opposite approach via whitelisting and trying to make security sexier so more people buy-in.
Guillermo talks about performance in single-page apps, optimistic UIs and reactivity.
John covers Validation, linting and TypeScript.