Index: wp-includes/script-loader.php
===================================================================
--- wp-includes/script-loader.php	(revision 14173)
+++ wp-includes/script-loader.php	(working copy)
@@ -71,6 +71,9 @@
 	$scripts->add_data( 'sack', 'group', 1 );
 
 	$scripts->add( 'quicktags', "/wp-includes/js/quicktags$suffix.js", false, '20090307' );
+	$scripts->add( 'quicktags-rtl', "/wp-includes/js/quicktags-rtl$suffix.js", array('quicktags'), '20100421');
+	$scripts->add_data( 'quicktags-rtl', 'group', 1 );
+	
 	$scripts->localize( 'quicktags', 'quicktagsL10n', array(
 		'quickLinks' => __('(Quick Links)'),
 		'wordLookup' => __('Enter a word to look up:'),
Index: wp-admin/admin-header.php
===================================================================
--- wp-admin/admin-header.php	(revision 14173)
+++ wp-admin/admin-header.php	(working copy)
@@ -52,6 +52,8 @@
 if ( in_array( $pagenow, array('post.php', 'post-new.php') ) ) {
 	add_action( 'admin_print_footer_scripts', 'wp_tiny_mce', 25 );
 	wp_enqueue_script('quicktags');
+	if ( 'rtl' == get_bloginfo( 'text_direction' ) )
+		wp_enqueue_script('quicktags-rtl');
 }
 
 do_action('admin_enqueue_scripts', $hook_suffix);
Index: wp-includes/js/quicktags-rtl.dev.js
===================================================================
--- wp-includes/js/quicktags-rtl.dev.js	(revision 0)
+++ wp-includes/js/quicktags-rtl.dev.js	(revision 0)
@@ -0,0 +1,20 @@
+function edToggleRTL(myField) {
+	myField.focus();
+	var currentDirection = myField.style.direction;
+	if (currentDirection == 'ltr')
+		myField.style.direction = 'rtl'
+	else
+		myField.style.direction = 'ltr'
+}
+
+var ed_toolbar = document.getElementById("ed_toolbar");
+if (ed_toolbar) {
+  var RTLButton = document.createElement('input');
+  RTLButton.type = 'button';
+  RTLButton.value = 'RTL/LTR';
+  RTLButton.onclick = function(){edToggleRTL(edCanvas)};
+  RTLButton.className = 'ed_button';
+  RTLButton.title = 'Toogle RTL/LTR';
+  RTLButton.id = 'ed_ToggleRTL';
+  ed_toolbar.appendChild(RTLButton);
+}
\ No newline at end of file