Mostrar posts relacionados por categoria no WordPress

<!-- Entradas relacionadas -->
<?php
//para poner en el loop, muestra 5 titulos de post relacionados con la primera tag del post actual
$tags = wp_get_post_tags($post->ID);
if ($tags) {
  echo '<h3>Artículos relacionados:</h3>';
  $first_tag = $tags[0]->term_id;
  $args=array(
	'tag__in' => array($first_tag),
	'post__not_in' => array($post->ID),
	'showposts'=>5,
	'caller_get_posts'=>1
   );
  $my_query = new WP_Query($args);
  if( $my_query->have_posts() ) {
	while ($my_query->have_posts()) : $my_query->the_post(); ?>
	  <p><a href="<?php the_permalink() ?>" rel="bookmark" title="Enlace permanente a <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
	  <?php
	endwhile;
  }
}
?>
<!-- Fin Entradas relacionadas -->

<?php query_posts('cat=X&showposts=10'); ?>

  <?php while (have_posts()) : the_post(); ?>
    <!-- Do special_cat stuff... -->
  <?php endwhile;?>

    <?php $orig_post = $post;
    global $post;
    $categories = get_the_category($post->ID);
    if ($categories) {
    $category_ids = array();
    foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;

    $args=array(
    'category__in' => $category_ids,
    'post__not_in' => array($post->ID),
    'posts_per_page'=> 2, // Número de posts que se mostrarán.
    'caller_get_posts'=>1
    );

    $my_query = new wp_query( $args );
    if( $my_query->have_posts() ) {
    echo '<div id="related_posts"><h3>Posts Relacionados</h3><ul>';
    while( $my_query->have_posts() ) {
    $my_query->the_post();?>

    <li><div class="relatedthumb"><a href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_post_thumbnail(); ?></a></div>
    <div class="relatedcontent">
    <h3><a href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_title(); ?></a></h3>
    <?php the_time('M j, Y') ?>
    </div>
    </li>
    <?
    }
    echo '</ul></div>';
    }
    }
    $post = $orig_post;
    wp_reset_query(); ?>

    <?php $orig_post = $post;
    global $post;
    $categories = get_the_category($post->ID);
    if ($categories) {
    $category_ids = array();
    foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;

    $args=array(
    'category__in' => $category_ids,
    'post__not_in' => array($post->ID),
    'posts_per_page'=> 2, // Número de posts que se mostrarán.
    'caller_get_posts'=>1
    );

    $my_query = new wp_query( $args );
    if( $my_query->have_posts() ) {
    echo '<div id="related_posts"><h3>Posts Relacionados</h3><ul>';
    while( $my_query->have_posts() ) {
    $my_query->the_post();?>

    <li>
    <div class="relatedcontent">
    <h3><a href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_title(); ?></a></h3>
    <?php the_time('M j, Y') ?>
    </div>
    </li>
    <?
    }
    echo '</ul></div>';
    }
    }
    $post = $orig_post;
    wp_reset_query(); ?>

<?php the_time('M j, Y') ?>