Mac + grunt 0.4.0 + grunt-devtools + grunt-contrib-livereload。 livereload の拡張機能を On にしつつ、devtools で livereload を開始すると livereload.js が読み込めずに自動リロードが機能しなくなる為、ブロウザの再読み込みを追加

Gruntfile.js

module.exports = function(grunt) {
  'use strict';

  var path        = require('path'),
      lrSnippet   = require('grunt-contrib-livereload/lib/utils').livereloadSnippet,
      folderMount = function folderMount(connect, point) {
        return connect.static(path.resolve(point));
      };

  grunt.initConfig({
    connect: {
      livereload: {
        options: {
          port: 9001,
          middleware: function(connect, options) {
            return [lrSnippet, folderMount(connect, '.')]
          }
        }
      }
    },
    regarde: {
      fred: {
        files: ['*.html', '*.js'],
        tasks: ['livereload']
      },
    },
  });

  grunt.loadNpmTasks('grunt-devtools');
  grunt.loadNpmTasks('grunt-regarde');
  grunt.loadNpmTasks('grunt-contrib-connect');
  grunt.loadNpmTasks('grunt-contrib-livereload');

  grunt.registerTask('autoreload', ['browser-reload', 'livereload-start', 'connect', 'regarde']);
  grunt.registerTask('default', 'devtools');

  // 参考：http://qiita.com/items/47100ac2ad4737770731
  grunt.registerTask('browser-reload', 'reload Google Chrome (OS X)', function() {
    require('child_process').exec('osascript -e \'tell application \"Google Chrome\" to tell the active tab of its first window to reload\'');
  });
};