These are the results from a source code comparison tool I wrote.
I am only counting application specific files, not framework files and not css files.
The size ignores all comments and all preceding and trailing white space on every source line.
It is intended to give a fair estimate of the application specific code size for each implementation.

Summary:
    Dojo is by far the worst from a complexity point of view with 17 files and 25K of code.
    Ion is the simplest requiring only a single file and 2.3K of code.
    Knockout is second most concise requiring only two files and 5.9K of code.
    Angular, Ember and Polymer all require about 5-9 files and 6-7K of code.
    React has average file count at 6, but code size is 50% above average at 9.6k.

React

    C:\Projects\todomvc\architecture-examples\react>node\Projects\ion\lib\test\sourceSize.js index.html js
    index.html : 1117
    js\app.jsx : 3067
    js\footer.jsx : 1038
    js\todoItem.jsx : 2107
    js\todoModel.js : 1514
    js\utils.js : 821
    ---------------------------------------
    Total Files : 6
    Total Bytes : 9664

AngularJS

    C:\Projects\todomvc\architecture-examples\angularjs>node \Projects\ion\lib\test\sourceSize.js index.
    html js
    index.html : 2720
    js\app.js : 358
    js\controllers\todoCtrl.js : 1840
    js\directives\todoEscape.js : 378
    js\directives\todoFocus.js : 388
    js\services\todoStorage.js : 369
    ---------------------------------------
    Total Files : 6
    Total Bytes : 6053

Polymer

    C:\Projects\todomvc\architecture-examples\polymer>node \Projects\ion\lib\test\sourceSize.js index.html elements
    index.html : 897
    elements\td-input.html : 497
    elements\td-item.html : 1320
    elements\td-model.html : 1598
    elements\td-todos.html : 2495
    ---------------------------------------
    Total Files : 5
    Total Bytes : 6807

EmberJS

    C:\Projects\todomvc\architecture-examples\emberjs>node \Projects\ion\lib\test\sourceSize.js index.html js
    index.html : 2808
    js\app.js : 152
    js\controllers\todos_controller.js : 899
    js\controllers\todos_list_controller.js : 394
    js\controllers\todo_controller.js : 870
    js\helpers\pluralize.js : 242
    js\models\todo.js : 142
    js\router.js : 718
    js\views\todo_input_component.js : 208
    ---------------------------------------
    Total Files : 9
    Total Bytes : 6433

KnockoutJS

    C:\Projects\todomvc\architecture-examples\knockoutjs>node \Projects\ion\lib\test\sourceSize.js index.html js
    index.html : 2371
    js\app.js : 3558
    ---------------------------------------
    Total Files : 2
    Total Bytes : 5929

JQuery

    C:\Projects\todomvc\architecture-examples\jquery>node \Projects\ion\lib\test\sourceSize.js index.html js
    index.html : 1924
    js\app.js : 4523
    ---------------------------------------
    Total Files : 2
    Total Bytes : 6447

Backbone

    C:\Projects\todomvc\architecture-examples\backbone>node \Projects\ion\lib\test\sourceSize.js index.html js
    index.html : 1985
    js\app.js : 142
    js\collections\todos.js : 439
    js\models\todo.js : 217
    js\routers\router.js : 295
    js\views\app-view.js : 2077
    js\views\todo-view.js : 1701
    ---------------------------------------
    Total Files : 7
    Total Bytes : 6856

Dojo

    C:\Projects\todomvc\architecture-examples\dojo>node \Projects\ion\lib\test\sourceSize.js index.html js\todo profiles
    index.html : 830
    js\todo\app.html : 1712
    js\todo\app.js : 5626
    js\todo\CssToggleWidget.js : 683
    js\todo\ctrl\RouteController.js : 1045
    js\todo\ctrl\TodoListRefController.js : 943
    js\todo\ctrl\TodoRefController.js : 2200
    js\todo\ctrl\_HashCompletedMixin.js : 765
    js\todo\form\CheckBox.js : 545
    js\todo\form\InlineEditBox.js : 1523
    js\todo\misc\HashSelectedConverter.js : 178
    js\todo\misc\LessThanOrEqualToConverter.js : 179
    js\todo\model\SimpleTodoModel.js : 2409
    js\todo\model\TodoModel.js : 3221
    js\todo\store\LocalStorage.js : 1439
    js\todo\TodoList.js : 792
    profiles\todomvc.profile.js : 293
    ---------------------------------------
    Total Files : 17
    Total Bytes : 24627*
    * removed by hand some files that appeared to be redundant.

Yui

    C:\Projects\todomvc\architecture-examples\yui>node \Projects\ion\lib\test\sourceSize.js index.html js/app.js js/models js/views
    index.html : 1874
    js/app.js : 3183
    js\models\todo.js : 420
    js\models\todolist.js : 547
    js\views\todoview.js : 1379
    ---------------------------------------
    Total Files : 5
    Total Bytes : 7403

Ion

    C:\Projects\ion\docs\samples>node \Projects\ion\lib\test\sourceSize.js TodoMVC.html
    TodoMVC.html : 2331
    ---------------------------------------
    Total Files : 1
    Total Bytes : 2314