[B_part]

I am a biologist (well, almost - one more year), and an atheist. This is my opinion:

1)About cloning organs: first of all this is still science fiction - many researchers are trying to move in thet direction, because they (and I) believe this can be done, but we can't even see it on the horizon. There are some major problems:
A-we don't know how to force stem cells into a precise develpoment pathway - the biochemical signaling is as yet almost completely obscure. Building an organ in vitro presumes the complete knowledge of those signaling pathways. Also I doubt anything could be accomplished this way even if we knew them, because it would be extremely difficult and expensive to simulate the complexity of a developing body.
B-the alternative is to grow these organs in host bodies, which of course wouldn't be human bodies but animals (pigs or monkeys). Monkeys would be better because they are more similar to us, but they are really expensive and difficult to keep. Pigs are the next best choice, and the cheapest. Obviously, no matter how similar we are to monkeys, there are still extremely heavy technical problems, the first of which is the tissue compatibility between animal and man.
C-Also, provided we can overcome these obstacles, there are still some dangers of diseases transmitted from the host species to man, and also of time - you cannot get a fully grown heart in less than one or two years in the most optimistic forecast.

This is the reason why biology is moving towards xenotransplantation. this is still far in the future, but the initial research goals have already been reached.