@croydon - I don't know that it would do much to lower the birthrate for puppies. I think that's mainly due to the kinds of people who wouldn't get their pet cloned anyway.
But it brings up one of the things that really scares me about this kind of technology. It can lead to people living longer, because of replacement organs and things like that, but it's always going to be expensive. I can't imagine we're close to the time when it will be cheap to order a new cloned liver.
Which means that it's going to give even more of an advantage to the rich and create even greater divides in the class system.
There are already children who can't do as well in school because they can't afford to buy lunch. Those kids might eventually be competing against kids whose genes were manipulated to be super-smart or athletic because their parents could afford to do so.