Use drupal_add_link instead of ugly XML icon on search result pages

This is a pity, as it is no longer obvious an RSS feed is available after a search is done. Would have appreciated if it was an option to be set by the admin to either the icon (or an RSS icon) or not.

Agreed. Different browsers handle this in different ways. Chrome doesn't show any indication there is a feed.

Here's some code that you can put in a custom module's form_alter() function:

// Add a 'Receive updates for this search' link to the search form. Uses the OpenSearch
  // module to create the feed.
  if (($form_id == 'search_form') && module_exists('opensearch')) {
    $path = $_SERVER['REQUEST_URI'];
    global $base_url;
    $opensearch_path = $base_url . preg_replace('/^\/search\//', '/opensearch/', $path);
    $feed_link = '<img src="/path_to_your/feed.png" /> Receive updates for this search';
    $form['opensearch_feed'] = array(
      '#value' => l($feed_link, $opensearch_path, array('html' => TRUE)),
    );
  }