How to get all linked nodes from all terms in a vocabulary
As "all linked nodes from all terms" are in my case the same as "all nodes of a content type", I solved my problem this way:

&lt;?php
function themename_preprocess_node_news_overview(&amp;$vars) {
  $results = db_query("SELECT nid, type FROM {node} WHERE type = 'news_post';");
  $tmp = array();
  foreach ($results as $result) {
    $tmp[] = $result-&gt;nid;
  }
  $vars['content'] = node_view_multiple(node_load_multiple($tmp), 'teaser');
}
?&gt;