Index: wp-admin/import/wordpress.php
===================================================================
--- wp-admin/import/wordpress.php	(revision 12320)
+++ wp-admin/import/wordpress.php	(working copy)
@@ -599,6 +599,7 @@
 			$key   = $this->get_tag( $p, 'wp:meta_key' );
 			$value = $this->get_tag( $p, 'wp:meta_value' );
 			$value = stripslashes($value); // add_post_meta() will escape.
+			$value = maybe_unserialize($value);
 
 			$this->process_post_meta($post_id, $key, $value);