Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 7826)
+++ wp-includes/comment.php	(working copy)
@@ -593,10 +593,7 @@
 	if ( ! isset($user_id) )
 		$user_id = 0;
 
-	$result = $wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->comments
-	(comment_post_ID, comment_author, comment_author_email, comment_author_url, comment_author_IP, comment_date, comment_date_gmt, comment_content, comment_approved, comment_agent, comment_type, comment_parent, user_id)
-	VALUES (%d, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %d, %d)",
-	$comment_post_ID, $comment_author, $comment_author_email, $comment_author_url, $comment_author_IP, $comment_date, $comment_date_gmt, $comment_content, $comment_approved, $comment_agent, $comment_type, $comment_parent, $user_id) );
+	$wpdb->insert($wpdb->comments, compact('comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_author_IP', 'comment_date', 'comment_date_gmt', 'comment_content', 'comment_approved', 'comment_agent', 'comment_type', 'comment_parent', 'user_id'));
 
 	$id = (int) $wpdb->insert_id;
 
@@ -719,15 +716,16 @@
 function wp_set_comment_status($comment_id, $comment_status) {
 	global $wpdb;
 
+	$update = false;
 	switch ( $comment_status ) {
 		case 'hold':
-			$query = $wpdb->prepare("UPDATE $wpdb->comments SET comment_approved='0' WHERE comment_ID = %d LIMIT 1", $comment_id);
+			$update = array('comment_approved' => '0');
 			break;
 		case 'approve':
-			$query = $wpdb->prepare("UPDATE $wpdb->comments SET comment_approved='1' WHERE comment_ID = %d LIMIT 1", $comment_id);
+			$update = array('comment_approved' => '1');
 			break;
 		case 'spam':
-			$query = $wpdb->prepare("UPDATE $wpdb->comments SET comment_approved='spam' WHERE comment_ID = %d LIMIT 1", $comment_id);
+			$update = array('comment_approved' => 'spam');
 			break;
 		case 'delete':
 			return wp_delete_comment($comment_id);
@@ -736,7 +734,7 @@
 			return false;
 	}
 
-	if ( !$wpdb->query($query) )
+	if ( $update && ! $wpdb->update($wpdb->comments, $update, array('comment_ID' => $comment_id)) )
 		return false;
 
 	clean_comment_cache($comment_id);
@@ -781,23 +779,7 @@
 
 	$comment_date_gmt = get_gmt_from_date($comment_date);
 
-	$wpdb->query( $wpdb->prepare("UPDATE $wpdb->comments SET
-			comment_content      = %s,
-			comment_author       = %s,
-			comment_author_email = %s,
-			comment_approved     = %s,
-			comment_author_url   = %s,
-			comment_date         = %s,
-			comment_date_gmt     = %s
-		WHERE comment_ID = %d",
-			$comment_content,
-			$comment_author,
-			$comment_author_email,
-			$comment_approved,
-			$comment_author_url,
-			$comment_date,
-			$comment_date_gmt,
-			$comment_ID) );
+	$wpdb->update($wpdb->comments, compact('comment_content', 'comment_author', 'comment_author_email', 'comment_approved', 'comment_author_url', 'comment_date', 'comment_date_gmt'), compact('comment_ID') );
 
 	$rval = $wpdb->rows_affected;
 
@@ -1053,7 +1035,7 @@
 	$to_ping = get_to_ping($post_id);
 	$pinged  = get_pung($post_id);
 	if ( empty($to_ping) ) {
-		$wpdb->query( $wpdb->prepare("UPDATE $wpdb->posts SET to_ping = '' WHERE ID = %d", $post_id) );
+		$wpdb->update($wpdb->posts, array('to_ping' => ''), array('ID' => $post_id) ); 
 		return;
 	}
 
Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 7826)
+++ wp-includes/functions.php	(working copy)
@@ -328,7 +328,8 @@
 		wp_cache_set( $option_name, $newvalue, 'options' );
 	}
 
-	$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->options SET option_value = %s WHERE option_name = %s", $newvalue, $option_name ) );
+	$wpdb->update($wpdb->options, array('option_value' => $newvalue), array('option_name' => $option_name) );
+
 	if ( $wpdb->rows_affected == 1 ) {
 		do_action( "update_option_{$option_name}", $oldvalue, $_newvalue );
 		return true;
@@ -370,7 +371,7 @@
 		wp_cache_set( 'notoptions', $notoptions, 'options' );
 	}
 
-	$wpdb->query( $wpdb->prepare( "INSERT INTO $wpdb->options (option_name, option_value, autoload) VALUES (%s, %s, %s)", $name, $value, $autoload ) );
+	$wpdb->insert($wpdb->options, array('option_name' => $name, 'option_value' => $value, 'autoload' => $autoload) );
 
 	do_action( "add_option_{$name}", $name, $value ); 
 	return;
@@ -528,8 +529,7 @@
 				$allowed_types = array( 'video', 'audio' );
 				if ( in_array( substr( $type, 0, strpos( $type, "/" ) ), $allowed_types ) ) {
 					$meta_value = "$url\n$len\n$type\n";
-					$wpdb->query( $wpdb->prepare( "INSERT INTO `$wpdb->postmeta` ( `post_id` , `meta_key` , `meta_value` )
-					VALUES ( %d, 'enclosure' , %s)", $post_ID, $meta_value ) );
+					$wpdb->insert($wpdb->postmeta, array('post_id' => $post_ID, 'meta_key' => 'enclosure', 'meta_value' => $meta_value) );
 				}
 			}
 		}
Index: wp-includes/pluggable.php
===================================================================
--- wp-includes/pluggable.php	(revision 7826)
+++ wp-includes/pluggable.php	(working copy)
@@ -1196,8 +1196,8 @@
 	global $wpdb;
 
 	$hash = wp_hash_password($password);
-	$query = $wpdb->prepare("UPDATE $wpdb->users SET user_pass = %s, user_activation_key = '' WHERE ID = %d", $hash, $user_id);
-	$wpdb->query($query);
+	$wpdb->update($wpdb->users, array('user_pass' => $hash, 'user_activation_key' => ''), array('ID' => $user_id) );
+
 	wp_cache_delete($user_id, 'users');
 }
 endif;
Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 7826)
+++ wp-includes/post.php	(working copy)
@@ -378,7 +378,7 @@
 	global $wpdb;
 
 	$post_type = sanitize_post_field('post_type', $post_type, $post_id, 'db');
-	$return = $wpdb->query( $wpdb->prepare("UPDATE $wpdb->posts SET post_type = %s WHERE ID = %d", $post_type, $post_id) );
+	$return = $wpdb->update($wpdb->posts, array('post_type' => $post_type), array('ID' => $post_id) );
 
 	if ( 'page' == $post_type )
 		clean_page_cache($post_id);
Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 7826)
+++ wp-includes/taxonomy.php	(working copy)
@@ -1191,7 +1191,7 @@
 		} else {
 			// The alias isn't in a group, so let's create a new one and firstly add the alias term to it.
 			$term_group = $wpdb->get_var("SELECT MAX(term_group) FROM $wpdb->terms") + 1;
-			$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->terms SET term_group = %d WHERE term_id = %d", $term_group, $alias->term_id ) );
+			$wpdb->update($wpdb->terms, compact('term_group'), array('term_id' => $alias->term_id) );
 		}
 	}
 
Index: wp-includes/user.php
===================================================================
--- wp-includes/user.php	(revision 7826)
+++ wp-includes/user.php	(working copy)
@@ -189,15 +189,12 @@
 	}
 
 	$cur = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->usermeta WHERE user_id = %d AND meta_key = %s", $user_id, $meta_key) );
-	if ( !$cur ) {
-		$wpdb->query( $wpdb->prepare("INSERT INTO $wpdb->usermeta ( user_id, meta_key, meta_value )
-		VALUES
-		( %d, %s, %s )", $user_id, $meta_key, $meta_value) );
-	} else if ( $cur->meta_value != $meta_value ) {
-		$wpdb->query( $wpdb->prepare("UPDATE $wpdb->usermeta SET meta_value = %s WHERE user_id = %d AND meta_key = %s", $meta_value, $user_id, $meta_key) );
-	} else {
+	if ( !$cur )
+		$wpdb->insert($wpdb->usermeta, compact('user_id', 'meta_key', 'meta_value') );
+	else if ( $cur->meta_value != $meta_value )
+		$wpdb->update($wpdb->usermeta, compact('meta_value'), compact('user_id', 'meta_key') );
+	else
 		return false;
-	}
 
 	wp_cache_delete($user_id, 'users');
 
Index: wp-login.php
===================================================================
--- wp-login.php	(revision 7826)
+++ wp-login.php	(working copy)
@@ -96,7 +96,7 @@
 		$key = wp_generate_password();
 		do_action('retrieve_password_key', $user_login, $key);
 		// Now insert the new md5 key into the db
-		$wpdb->query($wpdb->prepare("UPDATE $wpdb->users SET user_activation_key = %s WHERE user_login = %s", $key, $user_login));
+		$wpdb->update($wpdb->users, array('user_activation_key' => $key), array('user_login' => $user_login));
 	}
 	$message = __('Someone has asked to reset the password for the following site and username.') . "\r\n\r\n";
 	$message .= get_option('siteurl') . "\r\n\r\n";
Index: xmlrpc.php
===================================================================
--- xmlrpc.php	(revision 7826)
+++ xmlrpc.php	(working copy)
@@ -1352,7 +1352,7 @@
 		if( is_array( $attachments ) ) {
 			foreach( $attachments as $file ) {
 				if( strpos( $post_content, $file->guid ) !== false ) {
-					$wpdb->query( $wpdb->prepare("UPDATE {$wpdb->posts} SET post_parent = %d WHERE ID = %d", $post_ID, $file->ID) );
+					$wpdb->update($wpdb->posts, array('post_parent' => $post_ID), array('ID' => $file->ID) );
 				}
 			}
 		}