Index: wp-includes/class-http.php
===================================================================
--- wp-includes/class-http.php	(revision 20037)
+++ wp-includes/class-http.php	(working copy)
@@ -1689,6 +1689,8 @@
 
 		if ( function_exists( 'gzdecode' ) )
 			$type[] = 'gzip;q=0.5';
+			
+		$type = apply_filters( 'wp_http_accept_encoding', $type );
 
 		return implode(', ', $type);
 	}