Index: src/wp-admin/includes/class-wp-upgrader.php
===================================================================
--- src/wp-admin/includes/class-wp-upgrader.php	(revision 25828)
+++ src/wp-admin/includes/class-wp-upgrader.php	(working copy)
@@ -1402,7 +1402,7 @@
 	}
 
 	// Determines if this WordPress Core version should update to $offered_ver or not
-	static function should_upgrade_to_version( $offered_ver /* x.y.z */ ) {
+	static function should_update_to_version( $offered_ver /* x.y.z */ ) {
 		include ABSPATH . WPINC . '/version.php'; // $wp_version; // x.y.z
 
 		$current_branch = implode( '.', array_slice( preg_split( '/[.-]/', $wp_version  ), 0, 2 ) ); // x.y
@@ -1551,11 +1551,11 @@
 }
 
 /**
- * WordPress automatic background upgrader.
+ * WordPress automatic background updater.
  *
  * @since 3.7.0
  */
-class WP_Automatic_Upgrader {
+class WP_Background_Updater {
 
 	protected $update_results = array();
 
@@ -1570,7 +1570,7 @@
 		// More fine grained control can be done through the WP_AUTO_UPDATE_CORE constant and filters.
 		$disabled = defined( 'AUTOMATIC_UPDATES_DISABLED' ) && AUTOMATIC_UPDATES_DISABLED;
 
-		return apply_filters( 'auto_upgrader_disabled', $disabled );
+		return apply_filters( 'auto_updates_disabled', $disabled );
 	}
 
 	/**
@@ -1600,17 +1600,17 @@
 					break 2;
 			}
 		}
-		return apply_filters( 'auto_upgrade_is_vcs_checkout', $checkout, $context );
+		return apply_filters( 'auto_updates_is_vcs_checkout', $checkout, $context );
 	}
 
 	/**
-	 * Tests to see if we can and should upgrade a specific item.
+	 * Tests to see if we can and should update a specific item.
 	 */
-	function should_upgrade( $type, $item, $context ) {
+	function should_update( $type, $item, $context ) {
 		if ( $this->is_disabled() )
 			return false;
 
-		// Checks to see if WP_Filesystem is set up to allow unattended upgrades.
+		// Checks to see if WP_Filesystem is set up to allow unattended updates.
 		$skin = new Automatic_Upgrader_Skin;
 		if ( ! $skin->request_filesystem_credentials( false, $context ) )
 			return false;
@@ -1621,21 +1621,21 @@
 		// Next up, do we actually have it enabled for this type of update?
 		switch ( $type ) {
 			case 'language':
-				$upgrade = ! empty( $item->autoupdate );
+				$update = ! empty( $item->autoupdate );
 				break;
 			case 'core':
-				$upgrade = Core_Upgrader::should_upgrade_to_version( $item->current );
+				$update = Core_Upgrader::should_update_to_version( $item->current );
 				break;
 			default:
 			case 'plugin':
 			case 'theme':
-				$upgrade = false;
+				$update = false;
 				break;
 		}
 
 		// And does the user / plugins want it?
-		// Plugins may filter on 'auto_upgrade_plugin', and check the 2nd param, $item, to only enable it for certain Plugins/Themes
-		if ( ! apply_filters( 'auto_upgrade_' . $type, $upgrade, $item ) )
+		// Plugins may filter on 'auto_update_plugin', and check the 2nd param, $item, to only enable it for certain Plugins/Themes
+		if ( ! apply_filters( 'auto_update_' . $type, $update, $item ) )
 			return false;
 
 		// If it's a core update, are we actually compatible with its requirements?
@@ -1655,13 +1655,13 @@
 		return true;
 	}
 
-	function upgrade( $type, $item ) {
+	function update( $type, $item ) {
 
-		$skin = new Automatic_Upgrader_Skin();
+		$skin = new Automatic_Upgrader_Skin;
 
 		switch ( $type ) {
 			case 'core':
-				// The Core upgrader doesn't use the Upgrader's skin during the actual main part of the upgrade, instead, firing a filter
+				// The Core upgrader doesn't use the Upgrader's skin during the actual main part of the upgrade, instead, firing a filter.
 				add_filter( 'update_feedback', array( $skin, 'feedback' ) );
 				$upgrader = new Core_Upgrader( $skin );
 				$context  = ABSPATH;
@@ -1680,8 +1680,8 @@
 				break;
 		}
 
-		// Determine whether we can and should perform this upgrade.
-		if ( ! $this->should_upgrade( $type, $item, $context ) )
+		// Determine whether we can and should perform this update.
+		if ( ! $this->should_update( $type, $item, $context ) )
 			return false;
 
 		switch ( $type ) {
@@ -1733,7 +1733,7 @@
 	}
 
 	/**
-	 * Kicks off a upgrade request for each item in the upgrade "queue"
+	 * Kicks off a update request for each item in the update "queue".
 	 */
 	function run() {
 		global $wpdb;
@@ -1741,7 +1741,7 @@
 		if ( ! is_main_network() || ! is_main_site() )
 			return;
 
-		$lock_name = 'auto_upgrader.lock';
+		$lock_name = 'auto_updater.lock';
 
 		// Try to lock
 		$lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'no') /* LOCK */", $lock_name, time() ) );
@@ -1772,7 +1772,7 @@
 		$plugin_updates = get_site_transient( 'update_plugins' );
 		if ( $plugin_updates && !empty( $plugin_updates->response ) ) {
 			foreach ( array_keys( $plugin_updates->response ) as $plugin ) {
-				$this->upgrade( 'plugin', $plugin );
+				$this->update( 'plugin', $plugin );
 			}
 			// Force refresh of plugin update information
 			wp_clean_plugins_cache();
@@ -1783,13 +1783,13 @@
 		$theme_updates = get_site_transient( 'update_themes' );
 		if ( $theme_updates && !empty( $theme_updates->response ) ) {
 			foreach ( array_keys( $theme_updates->response ) as $theme ) {
-				$this->upgrade( 'theme', $theme );
+				$this->update( 'theme', $theme );
 			}
 			// Force refresh of theme update information
 			wp_clean_themes_cache();
 		}
 
-		// Next, Process any core upgrade
+		// Next, Process any core update
 		wp_version_check(); // Check for Core updates
 		$extra_update_stats = array();
 		$core_update = find_core_auto_update();
@@ -1797,7 +1797,7 @@
 		if ( $core_update ) {
 			$start_time = time();
 
-			$core_update_result = $this->upgrade( 'core', $core_update );
+			$core_update_result = $this->update( 'core', $core_update );
 			delete_site_transient( 'update_core' );
 
 			$extra_update_stats['success'] = is_wp_error( $core_update_result ) ? $core_update_result->get_error_code() : true;
@@ -1826,7 +1826,7 @@
 		$language_updates = wp_get_translation_updates();
 		if ( $language_updates ) {
 			foreach ( $language_updates as $update ) {
-				$this->upgrade( 'language', $update );
+				$this->update( 'language', $update );
 			}
 
 			// Clear existing caches
@@ -1850,9 +1850,9 @@
 		if ( empty( $this->update_results ) )
 			return;
 
-		$upgrade_count = 0;
-		foreach ( $this->update_results as $type => $upgrades )
-			$upgrade_count += count( $upgrades );
+		$update_count = 0;
+		foreach ( $this->update_results as $type => $updates )
+			$update_count += count( $updates );
 
 		$body = array();
 		$failures = 0;
@@ -1910,20 +1910,20 @@
 			$subject = sprintf( '[%s] Background updates have finished', get_bloginfo( 'name' ) );
 		}
 
-		$body[] = 'UPGRADE LOG';
-		$body[] = '===========';
+		$body[] = 'UPDATE LOG';
+		$body[] = '==========';
 		$body[] = '';
 
 		foreach ( array( 'core', 'plugin', 'theme', 'language' ) as $type ) {
 			if ( ! isset( $this->update_results[ $type ] ) )
 				continue;
-			foreach ( $this->update_results[ $type ] as $upgrade ) {
-				$body[] = $upgrade->name;
-				$body[] = str_repeat( '-', strlen( $upgrade->name ) );
-				foreach ( $upgrade->messages as $message )
+			foreach ( $this->update_results[ $type ] as $update ) {
+				$body[] = $update->name;
+				$body[] = str_repeat( '-', strlen( $update->name ) );
+				foreach ( $update->messages as $message )
 					$body[] = "  " . html_entity_decode( str_replace( '&#8230;', '...', $message ) );
-				if ( is_wp_error( $upgrade->result ) )
-					$body[] = '  Error: [' . $upgrade->result->get_error_code() . '] ' . $upgrade->result->get_error_message();
+				if ( is_wp_error( $update->result ) )
+					$body[] = '  Error: [' . $update->result->get_error_code() . '] ' . $update->result->get_error_message();
 				$body[] = '';
 			}
 		}
Index: src/wp-admin/includes/update.php
===================================================================
--- src/wp-admin/includes/update.php	(revision 25828)
+++ src/wp-admin/includes/update.php	(working copy)
@@ -77,12 +77,12 @@
 	include_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
 
 	$auto_update = false;
-	$upgrader = new WP_Automatic_Upgrader;
+	$upgrader = new WP_Background_Updater;
 	foreach ( $updates->updates as $update ) {
 		if ( 'autoupdate' != $update->response )
 			continue;
 
-		if ( ! $upgrader->should_upgrade( 'core', $update, ABSPATH ) )
+		if ( ! $upgrader->should_update( 'core', $update, ABSPATH ) )
 			continue;
 
 		if ( ! $auto_update || version_compare( $update->current, $auto_update->current, '>' ) )
Index: src/wp-admin/update-core.php
===================================================================
--- src/wp-admin/update-core.php	(revision 25828)
+++ src/wp-admin/update-core.php	(working copy)
@@ -148,7 +148,7 @@
 
 		if ( wp_http_supports( 'ssl' ) ) {
 			require_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
-			$upgrader = new WP_Automatic_Upgrader;
+			$upgrader = new WP_Background_Updater;
 			$future_minor_update = (object) array(
 				'current'       => $wp_version . '.1-update-core.php',
 				'version'       => $wp_version . '.1-update-core.php',
@@ -155,7 +155,7 @@
 				'php_version'   => $required_php_version,
 				'mysql_version' => $required_mysql_version,
 			);
-			$should_auto_update = $upgrader->should_upgrade( 'core', $future_minor_update, ABSPATH );
+			$should_auto_update = $upgrader->should_update( 'core', $future_minor_update, ABSPATH );
 			if ( $should_auto_update )
 				echo ' ' . __( 'Future security updates will be applied automatically.' );
 		}
@@ -172,8 +172,8 @@
 
 	if ( isset( $updates[0] ) && $updates[0]->response == 'development' ) {
 		require_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
-		$upgrader = new WP_Automatic_Upgrader;
-		if ( wp_http_supports( 'ssl' ) && $upgrader->should_upgrade( 'core', $updates[0], ABSPATH ) )
+		$upgrader = new WP_Background_Updater;
+		if ( wp_http_supports( 'ssl' ) && $upgrader->should_update( 'core', $updates[0], ABSPATH ) )
 			echo '<div class="updated inline"><p><strong>BETA TESTERS:</strong> This site is set up to install updates of future beta versions automatically.</p></div>';
 	}
 
Index: src/wp-includes/update.php
===================================================================
--- src/wp-includes/update.php	(revision 25828)
+++ src/wp-includes/update.php	(working copy)
@@ -414,7 +414,7 @@
 	include_once ABSPATH . '/wp-admin/includes/admin.php';
 	include_once ABSPATH . '/wp-admin/includes/class-wp-upgrader.php';
 
-	$upgrader = new WP_Automatic_Upgrader;
+	$upgrader = new WP_Background_Updater;
 	if ( $upgrader->is_disabled() )
 		return;
 
