Add integration to use external wishlist service like wishsimply.com. Wishsimply is great as it has focused to be a utility service for the web shops and it is not trying to compete against them. Most other wishlist services are full of crap as they try to steal your customers to their own shop or others shops, by showing affiliate ads. 

Further wishsimply is not selling or giving user information away. So it would be nice to integrate to it instead of other services, that have more relaxed practices.