Version 2.0 of the wishlist module contains several new visibility protection features, including configuration options that can make it very difficult for your users to see the purchased status of their wishlist items.
Display configuration options have been added that allow you to control which columns appear in the wishlist table view and to control the number of rows that the table will have. A theme function has also been added to allow developers to change the display name shown for users in the wishlist module. You are also able to hide the currency field if your site does not require multiple currency support for wishlist nodes.
Several bugs have been fixed, including some important CSS layout errors and an access control error that allowed anonymous users to view the list even when they were not authorized to do so.
A new feature has been added to automatically remove items from the wishlist a certain number of days after the item has been fully purchased. This feature requires a database change, so be sure to run update.php (note: postgres support is incomplete as I only run with and test mysql).
There are now 'new' indicators on wishlist items in the same way forums and comments are flagged as new throughout the Drupal platform.
Code from Drupal 4.7 version has been optimised, but javascript (now jquerified) is now loaded on each page, whether needed or not. This is more reliable, at the expense of page-load overhead.