Index: wp-includes/formatting.php
===================================================================
--- wp-includes/formatting.php	(revision 19786)
+++ wp-includes/formatting.php	(working copy)
@@ -28,18 +28,34 @@
  */
 function wptexturize($text) {
 	global $wp_cockneyreplace;
-	static $opening_quote, $closing_quote, $en_dash, $em_dash, $default_no_texturize_tags, $default_no_texturize_shortcodes, $static_characters, $static_replacements, $dynamic_characters, $dynamic_replacements;
+	static $opening_quote, $closing_quote, $opening_single_quote, $closing_single_quote, $en_dash, $em_dash,
+		$apos, $prime, $double_prime, $default_no_texturize_tags, $default_no_texturize_shortcodes,
+		$static_characters, $static_replacements, $dynamic_characters, $dynamic_replacements;
 
 	// No need to set up these static variables more than once
 	if ( empty( $opening_quote ) ) {
-		/* translators: opening curly quote */
-		$opening_quote = _x('“', 'opening curly quote');
-		/* translators: closing curly quote */
-		$closing_quote = _x('”', 'closing curly quote');
+		/* translators: opening curly double quote */
+		$opening_quote = _x( '“', 'opening curly double quote' );
+		/* translators: closing curly double quote */
+		$closing_quote = _x( '”', 'closing curly double quote' );
+
+		/* translators: apostrophe, for example in 'cause or can't */
+		$apos = _x( '’', 'apostrophe' );
+
+		/* translators: prime, for example in 9' (nine feet) */
+		$prime = _x( '′', 'prime' );
+		/* translators: double prime, for example in 9" (nine inches) */
+		$double_prime = _x( '″', 'double prime' );
+
+		/* translators: opening curly single quote */
+		$opening_single_quote = _x( '‘', 'opening curly single quote' );
+		/* translators: closing curly single quote */
+		$closing_single_quote = _x( '’', 'closing curly single quote' );
+
 		/* translators: en dash */
-		$en_dash = _x('–', 'en dash');
+		$en_dash = _x( '–', 'en dash' );
 		/* translators: em dash */
-		$em_dash = _x('—', 'em dash');
+		$em_dash = _x( '—', 'em dash' );
 
 		$default_no_texturize_tags = array('pre', 'code', 'kbd', 'style', 'script', 'tt');
 		$default_no_texturize_shortcodes = array('code');
@@ -49,15 +65,28 @@
 			$cockney = array_keys($wp_cockneyreplace);
 			$cockneyreplace = array_values($wp_cockneyreplace);
 		} else {
-			$cockney = array("'tain't","'twere","'twas","'tis","'twill","'til","'bout","'nuff","'round","'cause");
-			$cockneyreplace = array("’tain’t","’twere","’twas","’tis","’twill","’til","’bout","’nuff","’round","’cause");
+			$cockney = array( "'tain't", "'twere", "'twas", "'tis", "'twill", "'til", "'bout", "'nuff", "'round", "'cause" );
+			$cockneyreplace = array( $apos . "tain" . $apos . "t", $apos . "twere", $apos . "twas", $apos . "tis", $apos . "twill", $apos . "til", $apos . "bout", $apos . "nuff", $apos . "round", $apos . "cause" );
 		}
 
-		$static_characters = array_merge( array('---', ' -- ', '--', ' - ', 'xn–', '...', '``', '\'\'', ' (tm)'), $cockney );
-		$static_replacements = array_merge( array($em_dash, ' ' . $em_dash . ' ', $en_dash, ' ' . $en_dash . ' ', 'xn--', '…', $opening_quote, $closing_quote, ' ™'), $cockneyreplace );
+		$static_characters = array_merge( array( '---', ' -- ', '--', ' - ', 'xn–', '...', '``', '\'\'', ' (tm)' ), $cockney );
+		$static_replacements = array_merge( array( $em_dash, ' ' . $em_dash . ' ', $en_dash, ' ' . $en_dash . ' ', 'xn--', '…', $opening_quote, $closing_quote, ' ™' ), $cockneyreplace );
 
-		$dynamic_characters = array('/\'(\d\d(?:&#8217;|\')?s)/', '/\'(\d)/', '/(\s|\A|[([{<]|")\'/', '/(\d)"/', '/(\d)\'/', '/(\S)\'([^\'\s])/', '/(\s|\A|[([{<])"(?!\s)/', '/"(\s|\S|\Z)/', '/\'([\s.]|\Z)/', '/\b(\d+)x(\d+)\b/');
-		$dynamic_replacements = array('&#8217;$1','&#8217;$1', '$1&#8216;', '$1&#8243;', '$1&#8242;', '$1&#8217;$2', '$1' . $opening_quote . '$2', $closing_quote . '$1', '&#8217;$1', '$1&#215;$2');
+		$dynamic_characters = array(
+			'/\'(\d\d(?:&#8217;|\')?s)/', // '99's
+			'/\'(\d)/', // '99 (year)
+			'/(\s|\A|[([{<]|")\'/', // opening single quote, even after (, {, <, [, etc.
+			'/(\d)"/', // 9" (double prime)
+			'/(\d)\'/', // 9' (prime)
+			'/(\S)\'([^\'\s])/', // Matt's (apos)
+			'/(\s|\A|[([{<])"(?!\s)/', // opening double quote, even after (, {, <, [, etc.
+			'/"(\s|\S|\Z)/', // closing double quote
+			'/\'([\s.]|\Z)/', // closing single quote
+			'/\b(\d+)x(\d+)\b/' // 9 x 9 (times)
+		);
+
+		$dynamic_replacements = array( $apos . '$1', $apos . '$1', '$1' . $opening_single_quote, '$1' . $double_prime, '$1' . $prime,
+			'$1' . $apos . '$2', '$1' . $opening_quote . '$2', $closing_quote . '$1', $closing_single_quote . '$1', '$1&#215;$2' );
 	}
 
 	// Transform into regexp sub-expression used in _wptexturize_pushpop_element