It appears that the option is still in the early planning stages, though. "Currently, publishing want actions is disabled, though the button does render," Waddington wrote on his blog.
When asked about the feature, a Facebook spokeswoman said "we're always testing new Platform features, however we have nothing new to announce."
Waddington speculated that Facebook could build "a universal wishlist that could be queried by other apps through the Graph API."
The option would likely be helpful for Facebook's ad partners. Add a product to your Facebook wishlist and the company that produces it could serve up discounts - or just keep tabs on interest. Or, peruse the wishlist of a friend for birthday or holiday gift ideas?