gistfile1.js

// Create view
Posts.views.add("latest", function (terms) {
  return {
    options: {sort: {lastCommentedAt: -1}}
  };
});

// Route controller
Posts.controllers.latest = Posts.controllers.list.extend({
  view: "latest"
});

// Create route
Router.route('/latest', {
  name: 'posts_latest',
  controller: Posts.controllers.latest
});

// Override default "/" route
Router.onBeforeAction(function () {
  if (Router.current().route.getName()==="posts_default") {
    this.render("posts_list_controller", {
      data: {
        terms: {
          view: 'latest', // ideally this should reuse Posts.controllers.latest's data
          limit: 10
        }
      }
    });
  } else {
    this.next();
  }
});