Magento – How to move review tab in product page

You are going into the right direction, but you need to do some modifications:

1. addToParentGroup and setTitle are used to show content in review so add this code below

   <action method="addToParentGroup"><group>detailed_info</group></action>
   <action method="setTitle" translate="value"><value>Reviews</value></action>
   

2. you need to change block alias name of block type review/product_view_list to product_additional_data_review as product_additional_data alias name already exists in product.

   <block type="review/product_view_list" name="product.info.product_additional_data_review" as="product_additional_data_review" template="review/product/view/list.phtml">
       <action method="addToParentGroup"><group>detailed_info</group></action>
       <action method="setTitle" translate="value"><value>Reviews</value></action>
   
       <block type="review/form" name="product.review.form" as="review_form">
           <block type="page/html_wrapper" name="product.review.form.fields.before" as="form_fields_before" translate="label">
               <label>Review Form Fields Before</label>
               <action method="setMayBeInvisible"><value>1</value></action>
           </block>
       </block>
   </block>
   

Not sure why this is, but I found that by including this <?php $_product = Mage::registry('product'); ?> above the code mentioned in the question. I was able to get it to work. I also moved all the code to it's own .phtml file so that it would only be included on the product view page by adding a couple lines to the local.xml Like so.

<catalog_product_view translate="label">
     <reference name="product.info">
        <block type="core/template" name="reviewCountTabBlock" template="catalog/product/view/tabs/review_count.phtml" />
    </reference>
</catalog_product_view>

Then on the view.phtml I added this:

    <?php echo $this->getChildHtml('reviewCountTabBlock') ?>

and in the new template catalog/product/view/tabs/review_count.phtml I added this:

    <?php $_product = Mage::registry('product'); ?>
<?php 
    // Add this code to get review count
    //$summary         = $this->getReviewsSummaryHtml($_product, false, true); 
    $reviewcount     = $_product->getRatingSummary()->getReviewsCount(); 
    $this->getLayout()->getBlock('product.info.tabs')->setReviewCount($reviewcount);
?>

And that cleaned everything up. I hope this helps others.