nevermind
SELECT ost.id, ost.orderId, ost.newStatus
FROM order_status_tracking AS ost
INNER JOIN order_status_tracking AS ost2 ON ost.orderId = ost2.orderId
WHERE ost.date >= '2004-12-29' AND ost.date <= '2004-12-29'
GROUP BY ost.id, ost.orderId, ost.newStatus
HAVING ost.id = MAX( ost2.id )
ORDER BY `ost`.`id`