Force an empty region to display
Omega does it this way:

in omega.info

settings[alpha_region_xxx_force] = ''


in `omega/alpha/includes/theme-settings-structure.inc

$form['alpha_settings']['structure'][$section][$zone]['regions'][$region]['alpha_region_' . $region . '_force'] = array(
  '#type' =&gt; 'checkbox',
  '#title' =&gt; t('Force this region to be rendered'),
  '#description' =&gt; t('Enabling this will always render this region, even if it is empty.'),
  '#default_value' =&gt; $item['force'],
);


Call alpha_alpha_page_structure_alter() in alpha_page_alter()

#omega/alpha/template.php
foreach ($theme-&gt;regions as $region =&gt; $item) {
    if (($item['force'] || !empty($vars[$region]))) {
      $temporary[$item['section']][$item['zone']][$region] = !empty($vars[$region]) ? $vars[$region] : array();
...


this way your code should be:

function THEMENAME_page_alter(&amp;$page) {
    $regions = system_region_list($GLOBALS['theme'], REGIONS_ALL);
    foreach ($regions as $region =&gt; $name) {
        $page[$region] = !empty($page[$region]) ? $page[$region] : array();
    }
}