I don't link much to bioethics/politics, because I think it's a field going in circles. But here's a very thought-provoking piece - the first I've read in a while:
"...Paul McHugh, one of the council's moderates, finds the idea gruesome. He calls the proposed creation a "weird genetic hybrid" that is "very embryolike" and has been engineered to die. Hurlbut replies, coldly but correctly, that according to the technical definition favored by opponents of stem-cell research, the thing can't die because it was never alive."