What is best practices for adding a variable to a region using Omega? Typically I would do something like the following:

//In template.php
mytheme_preprocess_region(&$vars) {
  $vars['pizza'] = 'NOM NOM NOM';
}

Then in region--content.tpl.php (as an example)

<?php print $pizza ?>

When I attempt this the variable ($pizza in the example) isn't defined as I would expect.

Comments

Try using this:

<?php
function mytheme_preprocess_region(&$vars) {
$theme = alpha_get_theme();
switch (
$vars['elements']['#region']) {
      case
'content':
       
$vars['pizza'] = 'yummy';
    }
}
?>