Hi repeng, They are similar, but different. A Watch List is all business. It's to keep an eye on a listing and see how it goes, if the item sells or not, if the seller relists, etc. Buyers can use their Watch List to monitor items they may be considering bidding on, to bid in the last few minutes of the auction. Sellers may Watch items to see if they sell and for how much. Your Wish List is more fun, to share with friends and family, on Facebook, and essentially go fishing for gifts.
See these eBay Help pages:
Watch List http://pages.ebay.ca/help/buy/watching-items.html
Wish List http://pages.ebay.ca/help/buy/wish-list.html
