Index: src/wp-includes/admin-bar.php
===================================================================
--- src/wp-includes/admin-bar.php	(revision 51243)
+++ src/wp-includes/admin-bar.php	(working copy)
@@ -839,6 +839,7 @@
  * Add "Add New" menu.
  *
  * @since 3.1.0
+ * @since x.x.x Added a New Site link for network installations.
  *
  * @param WP_Admin_Bar $wp_admin_bar
  */
@@ -909,6 +910,17 @@
 			)
 		);
 	}
+
+	if ( is_multisite() && current_user_can( 'create_sites' ) ) {
+		$wp_admin_bar->add_node(
+			array(
+				'parent' => 'new-content',
+				'id'     => 'add-new-site',
+				'title'  => _x( 'Site', 'add new from admin bar' ),
+				'href'   => network_admin_url( 'site-new.php' ),
+			)
+		);
+	}
 }
 
 /**