As an infrequent Pinterest user I see the value in it. The service in my opinion has the chance to become huge in the online e-commerce referral/purchase space. I can see your train of thinking by calling it a "glorified wishlist" but I think its bigger than that Pinterest becoming the ultimate place to window shop and given human nature that will always be something valuable
But to say that Pinterest is a novel and future-resistant shopping interface is foolish. We can do much better than this. It reeks the web 2.0, where content has no meaning.
Links, captions and pictures? Come on, any 12 year old has the ability to produce a better system than that.