Index: wp-admin/includes/template.php
===================================================================
--- wp-admin/includes/template.php	(revision 29598)
+++ wp-admin/includes/template.php	(working copy)
@@ -924,6 +924,32 @@
 
 	$page = $screen->id;
 
+	/**
+	 * Filter the meta box context.
+	 *
+	 * @since 4.1.0
+	 *
+	 * @param string $context The context within the screen where the meta box
+	 *                        should display. Possible values depending on the
+	 *                        current screen are 'normal', 'side' and 'advanced'.
+	 * @param string $id      Meta box ID.
+	 * @param string $page    The screen ID on which to display the meta box.
+	 */
+	$context = apply_filters( 'meta_box_context', $context, $id, $page );
+
+	/**
+	 * Filter the meta box priority.
+	 *
+	 * @since 4.1.0
+	 *
+	 * @param string $priority The priority within the context of the meta box.
+	 *                         This can be either 'high', 'core', 'default' or
+	 *                         'low'.
+	 * @param string $id       Meta box ID.
+	 * @param string $page     The screen ID on which to display the meta box.
+	 */
+	$priority = apply_filters( 'meta_box_priority', $priority, $id, $page );
+
 	if ( !isset($wp_meta_boxes) )
 		$wp_meta_boxes = array();
 	if ( !isset($wp_meta_boxes[$page]) )