Replacement for Drupal 6's $form_state['post'] in Drupal 7
$form_state['post'] in Drupal 6 contains the values of the $_POST global, and a quick look at Drupal 7 shows that when accessing a form via the post method, $form_state['input'] will contain that same array.  Side note: if it is accessed via the get method, this will contain $_GET.