Only God should give life and take life away. Cloning will end in distaster. Even if humans are in a vegetative state and have never been able to view the world, they still have thoughts, their brains still work. It's wrong and it is murder.
Medical science is all about researching to save the lives of people and to help them be healthy. Not to mention live life to its fullest. However, it is wrong to clone a human just for the organs. Especially if they are created and they do not know they are clones. It is sort of like cattle. Do they know they are going to be killed in order to feed us and provide money? On the other hand, is a life of an un-cloned human more important than one that is cloned?
As an animal lover myself, if cloning was affordable, I would probably be open to the idea of cloning my pet. Just to keep a part of them alive. It wouldn't be the same pet but it would be keeping the memory alive. It's not like they are going to harvest organs from an animal.
Considering the fact that so many people are on a waiting list for an organ transplant, cloning might be a good option. Maybe it is wrong but I would be willing to do anything to save the life of someone I really loved.
Personally, I can't picture the idea of taking vital organs from someone we created just for that purpose. Each clone was once a child and in my eyes that is the same as abortion.