Hi,
The wishlist is linked to the joomla user id and to the joomla session.
So, it is possible for guest users to have a wishlist, but if they loose their session, they would loose their wishlists too.
With Joomla accounts, the lost is not really possible and you can allow the joomla registration even if HikaShop is working with "no registration".
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.