Index: wp-admin/includes/meta-boxes.php
===================================================================
--- wp-admin/includes/meta-boxes.php	(revision 18700)
+++ wp-admin/includes/meta-boxes.php	(working copy)
@@ -527,12 +527,13 @@
 ?>
 <label class="screen-reader-text" for="post_author_override"><?php _e('Author'); ?></label>
 <?php
-	wp_dropdown_users( array(
+	$args = array(
 		'who' => 'authors',
 		'name' => 'post_author_override',
 		'selected' => empty($post->ID) ? $user_ID : $post->post_author,
 		'include_selected' => true
-	) );
+	);
+	wp_dropdown_users( apply_filters_ref_array('post_author_meta_box', $args) );
 }