define('WP_SITEURL', 'http://' . $_SERVER['SERVER_NAME']);
define('WP_HOME', 'http://' . $_SERVER['SERVER_NAME']);
Your site should now load as normal. Once you've successfully loaded it, you can remove the last of these three define statements.
If you had WordPress HTTPS (SSL) plugin installed prior to the move, you will need to add this line as well:
define('WPHTTPS_RESET', true);