detect_incorrect_source_model.php

<?php

require_once 'app/Mage.php';

Mage::init();

$attributes = Mage::getModel('eav/entity_attribute')->getCollection()
  ->addFieldToFilter('source_model', array('notnull' => true))
  ->addFieldToFilter('source_model', array('neq' => ''));
foreach ($attributes as $attribute) {
  $model = Mage::getModel($attribute->getSourceModel());
  if (!$model) {
    printf("Attribute '%s' has an invalid source_model\n", $attribute->getAttributeCode());
  }
}