Index: wp-admin/edit-tag-form.php
===================================================================
--- wp-admin/edit-tag-form.php	(revision 12942)
+++ wp-admin/edit-tag-form.php	(working copy)
@@ -10,11 +10,8 @@
 if ( !defined('ABSPATH') )
 	die('-1');
 
-if ( !current_user_can('manage_categories') )
-	wp_die(__('You do not have sufficient permissions to edit tags for this blog.'));
-
 if ( empty($tag_ID) ) { ?>
-	<div id="message" class="updated"><p><strong><?php _e('A tag was not selected for editing.'); ?></strong></p></div>
+	<div id="message" class="updated"><p><strong><?php printf( _x('A %s was not selected for editing.', '%s: singular taxonomy name'), $tax->singular_label); ?></strong></p></div>
 <?php
 	return;
 }
@@ -23,11 +20,11 @@
 	do_action('edit_category_form_pre', $tag );
 else
 	do_action('edit_tag_form_pre', $tag);
-do_action('edit_' . $taxonomy . '_form_pre', $tag, $taxonomy);  ?>
+do_action('edit_' . $taxonomy . '_form_pre', $tag, $taxonomy); ?>
 
 <div class="wrap">
 <?php screen_icon(); ?>
-<h2><?php _e('Edit Tag'); ?></h2>
+<h2><?php printf(_x('Edit %s', '%s: singular taxonomy name'), $tax->singular_label); ?></h2>
 <div id="ajax-response"></div>
 <form name="edittag" id="edittag" method="post" action="edit-tags.php" class="validate">
 <input type="hidden" name="action" value="editedtag" />
@@ -36,27 +33,30 @@
 <?php wp_original_referer_field(true, 'previous'); wp_nonce_field('update-tag_' . $tag_ID); ?>
 	<table class="form-table">
 		<tr class="form-field form-required">
-			<th scope="row" valign="top"><label for="name"><?php _e('Tag name') ?></label></th>
-			<td><input name="name" id="name" type="text" value="<?php if ( isset( $tag->name ) ) echo esc_attr($tag->name); ?>" size="40" aria-required="true" /></td>
+			<th scope="row" valign="top"><label for="name"><?php echo _x('Name', 'Taxonomy Name'); ?></label></th>
+			<td><input name="name" id="name" type="text" value="<?php if ( isset( $tag->name ) ) echo esc_attr($tag->name); ?>" size="40" aria-required="true" />
+			<p class="description"><?php _e('The name is how it appears on your site.'); ?></p></td>
 		</tr>
 <?php if ( !is_multisite() ) { ?>
 		<tr class="form-field">
-			<th scope="row" valign="top"><label for="slug"><?php _e('Tag slug') ?></label></th>
+			<th scope="row" valign="top"><label for="slug"><?php echo _x('Slug', 'Taxonomy Slug'); ?></label></th>
 			<td><input name="slug" id="slug" type="text" value="<?php if ( isset( $tag->slug ) ) echo esc_attr(apply_filters('editable_slug', $tag->slug)); ?>" size="40" />
 			<p class="description"><?php _e('The &#8220;slug&#8221; is the URL-friendly version of the name. It is usually all lowercase and contains only letters, numbers, and hyphens.'); ?></p></td>
 		</tr>
 <?php } ?>
-<?php if ( is_taxonomy_hierarchical($taxonomy) ) { ?>
+<?php if ( is_taxonomy_hierarchical($taxonomy) ) : ?>
 		<tr class="form-field">
-			<th scope="row" valign="top"><label for="parent"><?php _e('Category Parent') ?></label></th>
+			<th scope="row" valign="top"><label for="parent"><?php echo _x('Parent', 'Taxonomy Parent'); ?></label></th>
 			<td>
 				<?php wp_dropdown_categories(array('hide_empty' => 0, 'hide_if_empty' => false, 'name' => 'parent', 'orderby' => 'name', 'taxonomy' => $taxonomy, 'selected' => $tag->parent, 'exclude' => $tag->term_id, 'hierarchical' => true, 'show_option_none' => __('None'))); ?><br />
+				<?php if ( 'category' == $taxonomy ) : ?>
 				<span class="description"><?php _e('Categories, unlike tags, can have a hierarchy. You might have a Jazz category, and under that have children categories for Bebop and Big Band. Totally optional.'); ?></span>
+				<?php endif; ?>
 			</td>
 		</tr>
-<?php } ?>
+<?php endif; // is_taxonomy_hierarchical() ?>
 		<tr class="form-field">
-			<th scope="row" valign="top"><label for="description"><?php _e('Description') ?></label></th>
+			<th scope="row" valign="top"><label for="description"><?php echo _x('Description', 'Taxonomy Description'); ?></label></th>
 			<td><textarea name="description" id="description" rows="5" cols="50" style="width: 97%;"><?php echo esc_html($tag->description); ?></textarea><br />
 			<span class="description"><?php _e('The description is not prominent by default, however some themes may show it.'); ?></span></td>
 		</tr>
@@ -68,8 +68,8 @@
 		do_action('edit_' . $taxonomy . '_form_fields', $tag, $taxonomy);
 		?>
 	</table>
-<p class="submit"><input type="submit" class="button-primary" name="submit" value="<?php esc_attr_e('Update Tag'); ?>" /></p>
-<?php 
+<p class="submit"><input type="submit" class="button-primary" name="submit" value="<?php echo esc_attr( sprintf(_x('Update %s', '%s: singular taxonomy name'), $tax->singular_label)); ?>" /></p>
+<?php
 if ( 'category' == $taxonomy ) 
 	do_action('edit_category_form_', $tag);
 else
Index: wp-admin/edit-tags.php
===================================================================
--- wp-admin/edit-tags.php	(revision 12942)
+++ wp-admin/edit-tags.php	(working copy)
@@ -150,13 +150,15 @@
 
 require_once ('admin-header.php');
 
-$messages[1] = __('Tag added.');
-$messages[2] = __('Tag deleted.');
-$messages[3] = __('Tag updated.');
-$messages[4] = __('Tag not added.');
-$messages[5] = __('Tag not updated.');
-$messages[6] = __('Tags deleted.'); ?>
+$messages[1] = sprintf(_x('%s added.', '%s: singular taxonomy name'), $tax->singular_label);
+$messages[2] = sprintf(_x('%s deleted.', '%s: singular taxonomy name'), $tax->singular_label);
+$messages[3] = sprintf(_x('%s updated.', '%s: singular taxonomy name'), $tax->singular_label);
+$messages[4] = sprintf(_x('%s not added.', '%s: singular taxonomy name'), $tax->singular_label);
+$messages[5] = sprintf(_x('%s not updated.', '%s: singular taxonomy name'), $tax->singular_label);
+$messages[6] = sprintf(_x('%s deleted.', '%s: plural taxonomy name'), $tax->label);
 
+?>
+
 <div class="wrap nosubsub">
 <?php screen_icon(); ?>
 <h2><?php echo esc_html( $title );
@@ -174,9 +176,9 @@
 <input type="hidden" name="taxonomy" value="<?php echo esc_attr($taxonomy); ?>" />
 <input type="hidden" name="post_type" value="<?php echo esc_attr($post_type); ?>" />
 <p class="search-box">
-	<label class="screen-reader-text" for="tag-search-input"><?php _e( 'Search Tags' ); ?>:</label>
+	<label class="screen-reader-text" for="tag-search-input"><?php printf(_x('Search %s', '%s: plural taxonomy name'), $tax->label); ?>:</label>
 	<input type="text" id="tag-search-input" name="s" value="<?php _admin_search_query(); ?>" />
-	<input type="submit" value="<?php esc_attr_e( 'Search Tags' ); ?>" class="button" />
+	<input type="submit" value="<?php echo esc_attr( sprintf(_x('Search %s', '%s: plural taxonomy name'), $tax->label) ); ?>" class="button" />
 </p>
 </form>
 <br class="clear" />
@@ -234,17 +236,17 @@
 </div>
 
 <div class="clear"></div>
-
+<?php $table_type = 'category' == $taxonomy ? 'categories' : 'edit-tags'; ?>
 <table class="widefat tag fixed" cellspacing="0">
 	<thead>
 	<tr>
-<?php print_column_headers('edit-tags'); ?>
+<?php print_column_headers($table_type); ?>
 	</tr>
 	</thead>
 
 	<tfoot>
 	<tr>
-<?php print_column_headers('edit-tags', false); ?>
+<?php print_column_headers($table_type, false); ?>
 	</tr>
 	</tfoot>
 
@@ -272,6 +274,15 @@
 
 <br class="clear" />
 </form>
+
+<?php if ( 'category' == $taxonomy ) : ?>
+<div class="form-wrap"> 
+<p><?php printf(__('<strong>Note:</strong><br />Deleting a category does not delete the posts in that category. Instead, posts that were only assigned to the deleted category are set to the category <strong>%s</strong>.'), apply_filters('the_category', get_cat_name(get_option('default_category')))) ?></p> 
+<p><?php printf(__('Categories can be selectively converted to tags using the <a href="%s">category to tag converter</a>.'), 'admin.php?import=wp-cat2tag') ?></p> 
+</div> 
+<?php endif; ?>
+
+
 </div>
 </div><!-- /col-right -->
 
@@ -279,7 +290,7 @@
 <div class="col-wrap">
 
 <div class="tagcloud">
-<h3><?php _e('Popular Tags'); ?></h3>
+<h3><?php printf(_x('Popular %s', '%s: plural taxonomy name'), $tax->label); ?></h3>
 <?php
 if ( current_user_can($tax->edit_cap) )
 	wp_tag_cloud(array('taxonomy' => $taxonomy, 'link' => 'edit'));
@@ -288,7 +299,8 @@
 ?>
 </div>
 
-<?php if ( current_user_can($tax->edit_cap) ) {
+<?php
+if ( current_user_can($tax->edit_cap) ) {
 	if ( 'category' == $taxonomy )
 		do_action('add_category_form_pre', (object)array('parent' => 0) );
 	else
@@ -297,46 +309,46 @@
 ?>
 
 <div class="form-wrap">
-<h3><?php _e('Add a New Tag'); ?></h3>
+<h3><?php printf(_x('Add a New %s', '%s: singular taxonomy name'), $tax->singular_label); ?></h3>
 <form id="addtag" method="post" action="edit-tags.php" class="validate">
 <input type="hidden" name="action" value="add-tag" />
 <input type="hidden" name="taxonomy" value="<?php echo esc_attr($taxonomy); ?>" />
 <?php wp_nonce_field('add-tag'); ?>
 
 <div class="form-field form-required">
-	<label for="tag-name"><?php _e('Tag name') ?></label>
+	<label for="tag-name"><?php echo _x('Name', 'Taxonomy Name'); ?></label>
 	<input name="tag-name" id="tag-name" type="text" value="" size="40" aria-required="true" />
-	<p><?php _e('The name is how the tag appears on your site.'); ?></p>
+	<p><?php _e('The name is how it appears on your site.'); ?></p>
 </div>
-<?php if ( !is_multisite() ) { ?>
+<?php if ( !is_multisite() ) : ?>
 <div class="form-field">
-	<label for="slug"><?php _e('Tag slug') ?></label>
+	<label for="slug"><?php echo _x('Slug', 'Taxonomy Slug'); ?></label>
 	<input name="slug" id="slug" type="text" value="" size="40" />
 	<p><?php _e('The &#8220;slug&#8221; is the URL-friendly version of the name. It is usually all lowercase and contains only letters, numbers, and hyphens.'); ?></p>
 </div>
-<?php } ?>
-<?php if ( is_taxonomy_hierarchical($taxonomy) ) { ?>
+<?php endif; // is_multisite() ?>
+<?php if ( is_taxonomy_hierarchical($taxonomy) ) : ?>
 <div class="form-field">
-	<label for="category_parent"><?php _e('Category Parent') ?></label>
+	<label for="parent"><?php echo _x('Parent', 'Taxonomy Parent'); ?></label>
 	<?php wp_dropdown_categories(array('hide_empty' => 0, 'hide_if_empty' => false, 'taxonomy' => $taxonomy, 'name' => 'parent', 'orderby' => 'name', 'hierarchical' => true, 'show_option_none' => __('None'))); ?>
-	<p><?php _e('Categories, unlike tags, can have a hierarchy. You might have a Jazz category, and under that have children categories for Bebop and Big Band. Totally optional.'); ?></p>
+	<?php if ( 'category' == $taxonomy ) : ?>
+		<p><?php _e('Categories, unlike tags, can have a hierarchy. You might have a Jazz category, and under that have children categories for Bebop and Big Band. Totally optional.'); ?></p>
+	<?php endif; ?>
 </div>
-<?php } ?>
+<?php endif; // is_taxonomy_hierarchical() ?>
 <div class="form-field">
-	<label for="description"><?php _e('Description') ?></label>
+	<label for="description"><?php echo _x('Description', 'Taxonomy Description'); ?></label>
 	<textarea name="description" id="description" rows="5" cols="40"></textarea>
 	<p><?php _e('The description is not prominent by default; however, some themes may show it.'); ?></p>
 </div>
-
-<?php 
+<?php
 if ( 'category' == $taxonomy ) 
 	do_action('add_category_form_fields');
 else
 	do_action('add_tag_form_fields', $taxonomy);
 do_action('add_' . $taxonomy . '_form_fields', $taxonomy);
 ?>
-
-<p class="submit"><input type="submit" class="button" name="submit" id="submit" value="<?php esc_attr_e('Add Tag'); ?>" /></p>
+<p class="submit"><input type="submit" class="button" name="submit" id="submit" value="<?php echo esc_attr(sprintf(_x('Add %s', '%s: singular  taxonomy name'), $tax->singular_label)); ?>" /></p>
 <?php
 if ( 'category' == $taxonomy )
 	do_action('edit_category_form',	(object)array('parent' => 0) );
@@ -361,4 +373,4 @@
 
 include('admin-footer.php');
 
-?>
+?>
\ No newline at end of file
Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 12942)
+++ wp-includes/taxonomy.php	(working copy)
@@ -18,6 +18,7 @@
 	register_taxonomy( 'category', 'post', array(	'hierarchical' => true,
 												 	'update_count_callback' => '_update_post_term_count',
 													'label' => __('Categories'),
+													'singular_label' => __('Category'),
 													'query_var' => false,
 													'rewrite' => false
 												) ) ;
@@ -26,6 +27,7 @@
 												 	'hierarchical' => false,
 													'update_count_callback' => '_update_post_term_count',
 													'label' => __('Post Tags'),
+													'singular_label' => __('Post Tag'), //For the record, I'd prefer this to be changed to "Tags" and "Tag"
 													'query_var' => false,
 													'rewrite' => false
 												) ) ;
@@ -212,6 +214,9 @@
 		if ( empty($args[$cap]) )
 			$args[$cap] = 'manage_categories';
 	}
+	
+	if ( empty($args['singular_label']) )
+		$args['singular_label'] = $args['label'];
 
 	$args['name'] = $taxonomy;
 	$args['object_type'] = (array) $object_type;