Index: src/wp-admin/includes/class-wp-upgrader.php
===================================================================
--- src/wp-admin/includes/class-wp-upgrader.php	(revision 25778)
+++ src/wp-admin/includes/class-wp-upgrader.php	(working copy)
@@ -1750,9 +1750,13 @@
 			if ( is_wp_error( $core_update_result ) && 'rollback_was_required' == $core_update_result->get_error_code() ) {
 				$rollback_data = $core_update_result->get_error_data();
 				$extra_update_stats['success'] = is_wp_error( $rollback_data['update'] ) ? $rollback_data['update']->get_error_code() : $rollback_data['update'];
-				$extra_update_stats['rollback'] = is_wp_error( $rollback_data['rollback'] ) ? $rollback_data['rollback']->get_error_code() : true; // If it's not a WP_Error, the rollback was successful.
+				$extra_update_stats['success_data'] = is_wp_error( $rollback_data['update'] ) ? $rollback_data['update']->get_error_data() : false;
+				// If it's not a WP_Error, the rollback was successful.
+				$extra_update_stats['rollback'] = is_wp_error( $rollback_data['rollback'] ) ? $rollback_data['rollback']->get_error_code() : true;
+				$extra_update_stats['rollback_data'] = is_wp_error( $rollback_data['rollback'] ) ? $rollback_data['rollback']->get_error_data() : false;
 			}
 			$extra_update_stats['fs_method'] = $GLOBALS['wp_filesystem']->method;
+			$extra_update_stats['fs_method_forced'] = defined( 'FS_METHOD' ) || has_filter( 'fs_method' );
 			$extra_update_stats['time_taken'] = ( time() - $start_time );
 			$extra_update_stats['attempted'] = $core_update->version;
 		}
Index: src/wp-includes/update.php
===================================================================
--- src/wp-includes/update.php	(revision 25778)
+++ src/wp-includes/update.php	(working copy)
@@ -86,8 +86,12 @@
 		'multisite_enabled' => $multisite_enabled,
 	);
 
+	$post_body = array(
+		'translations' => json_encode( $translations ),
+	);
+
 	if ( $extra_stats )
-		$query = array_merge( $query, $extra_stats );
+		$post_body = array_merge( $post_body, $extra_stats );
 
 	$url = 'http://api.wordpress.org/core/version-check/1.7/?' . http_build_query( $query, null, '&' );
 	if ( wp_http_supports( array( 'ssl' ) ) )
@@ -100,11 +104,9 @@
 			'wp_install' => $wp_install,
 			'wp_blog' => home_url( '/' )
 		),
-		'body' => array(
-			'translations' => json_encode( $translations ),
-		),
+		'body' => $post_body,
 	);
-
+var_dump( compact( 'options', 'query' ) );
 	$response = wp_remote_post( $url, $options );
 
 	if ( is_wp_error( $response ) || 200 != wp_remote_retrieve_response_code( $response ) )