Entity Translation - create a translation for all existing nodes
A possible solution could be to use a custom module that uses hook_node_view, as in this example:

function yourmodule_node_view($node, $view_mode, $langcode){
   global $language;
   if (!empty($node-&gt;language) &amp;&amp; $node-&gt;language != $language-&gt;language) {
      drupal_goto('path/to/some/temporary/version');  
   }
}


What the content of such path/to/some/temporary/version node should be is up to you. E.g. you could point to some custom 404 page.