We're planning to make big changes in how assets are declared and managed in Drupal 8: Assetic (intro slides | repo) in core. drupal_add_css(), and drupal_add_js() - gone. Better mechanisms for declaring, organizing, and aggregating assets.

In this presentation, I'll demonstrate how these new systems are expected to work - especially Assetic, which will allow us to natively support SASS, Coffeescript, LESS, and more. I'll also discuss the new possibilities this new approach to assets opens up.