It depends. Sometimes I do in hopes that EF will bring it back if they can. I have a hope that if an item is on many wishlists then EF will look for a similar item to offer us. Usally I find plenty of things that I want that are still avalible.
I'll wishlist out of stock items. I'd totally forget about an item if it wasn't on my list. I also set an alert to let me know when an item is back in stock. I may not order right then but I can keep tabs and drool.