As you may know, AirBnb opensourced Rendr (http://nerds.airbnb.com/weve-open-sourced-rendr) which should enable server-side rendering of Backbone a
This new package https://github.com/a-lucas/angular.js-server allows you to pre-render an Angular application and send HTML to the client, that will then execute the jS code.
It supports caching per url and you can define rules to activate URL pre-rendering.
PS: I am the main contributor for this package.