Other than the 'yuck' factor, what's the real objection to all this? Have folks read too much Science Fiction where it all goes terribly wrong? Maybe it'll be fine. Grow organs in sheep, use them on ill people, folks get better, have a mutton dinner to celebrate!

Seriously, we wear sheep's wool and skin, crack chicken embryos into our batter to make it bake up nice and firm, rub animal oils into our skin and armpits to smell and look better. But use them for real medicine and suddenly "Whoa there! Lets think about this some more?"

I'm all for continuing until there's a problem, which probably won't ever happen.