Get next node in nodequeue
Should be something like getting the nid of the current node and then being $nid the node id of the current node and $sqid the queue id:

$pos = nodequeue_queue_position('work_order', $nid);
$nodes = nodequeue_load_nodes($sqid, FALSE, $pos+1, 1, TRUE);


It's untested so maybe you need to tweak the position and so.