--- wp-includes/class-oembed.php	Sun Apr 10 16:29:27 2011
+++ wp-includes/class-oembed.php	Sun Apr 10 17:16:34 2011
@@ -169,6 +169,8 @@
 		$provider = add_query_arg( 'maxheight', $args['height'], $provider );
 		$provider = add_query_arg( 'url', urlencode($url), $provider );
 
+		apply_filters( 'oembed_params_before_fetch', $provider, $url, $args );
+
 		foreach( array( 'json', 'xml' ) as $format ) {
 			$result = $this->_fetch_with_format( $provider, $format );
 			if ( is_wp_error( $result ) && 'not-implemented' == $result->get_error_code() )