To start, I am for fetal stem cell research. While cord stem cells have done some good, they've only been able to be used for blood diseases - certainly a benefit, but not as broad as fetal stem cells could be. Other adult stem cell uses have been very hit-or-miss.
We need to broaden the lines available for research, as the HoR has recently passed and Bush is threatening to veto. Of the sixty or so Bush "allowed" for federal research, we can only use about twenty or so - the others aren't viable. And of those twenty or so, many were "grown" using tissue from mice, which means using them in humans becomes more difficult and likely to be rejected. (I am nowhere near an expert on this topic - I think I've got the basic ideas straight but may be off in others. Check other science blogs for more specific information - say, Chris Mooney's.)
Many people are against fetal stem cell research for various reasons, but it seems a common thread is the one articulated by Andrew Sullivan, copied here in full b/c I can't find the link to it...
BUSH'S VETO: In my view, he's right to veto federal funding for embryonic stem cell research. There is a very clear principle here: do you take life to save lives? My conviction is that you don't, and that the human life in embryonic form is still human life. The idea of cloning embryos to experiment on them is morally repugnant; equally, using left-over, frozen embryos for the same purpose is using human beings as means, not ends. If that isn't a clear, moral line, then I don't know what is. My own religious faith in the dignity of human life is not necessary to support this argument, whatever the NYT says. We're all humans; whatever we believe about our origins or destiny, we can all agree that each of us deserves to be treated as ends in ourselves, not material for others' benefit. If we cede that principle, then we will slide (and have already slid) toward hideous forms of eugenics. Now I know many people disagree. But the pragmatic arguments they deploy - these embryos will be destroyed or kept in limbo anyway, they're teensy-weensy - don't circumvent the deeper moral issue. The only logical justification is an entirely utilitarian one, in which the use of "lesser" humans for the benefit of more developed ones is justified. But this begs an important question: in our society, there is no fundamental moral consensus any more, especially on contentious issues like these. Under those circumstances, it seems to me that the government should remain as neutral as possible between moral claims. The NYT interprets neutrality as funding embryonic stem cell research. That's a funny form of neutrality. In this case, the president has carved out a policy that is, indeed, about as neutral as it could be. If the private sector wants to pursue this course, it can; if individual states want to, ditto. But no American taxpayer should be required to fund from her own dollars what she regards as a moral outrage. Keep the feds out of it. Let the states and private sector do as they will.
Okay, my problem is this. These embryos should be treated as ends in themselves, i.e. as humans and not material, is Andrew's argument. If this is the case, shouldn't anyone who discards an embryo be arrested for murder? Shouldn't adults who agree to have their embryos discarded be arrested for child abuse? It seems the common argument is: These are people, they shouldn't be used for stem cell research; that's turning them into material. But if these same embryos are discarded, what are they then? It seems to be that there's a large logical gap there - they're human if they're to be used in fetal stem cell research, but they're not human if they're to be discarded. The intent determines the status.
The bill recently passed would call for permission to be given by the parents on embryos about to be discarded. This is not smash and extract science. People will have an informed choice about what to do - which makes it a lot like first trimester abortion; something Andrew does reluctantly support. (Again, I don't see a link on this, and I don't want to c&p another post, but the difference to him is that the embryo is in another person's body, and their liberty outweighs the fetus. See his site for the complete post.)
If you do feel that frozen embryos are really human, here's the question to ask yourself: You live next to a reproductive facility that has frozen embryos. It breaks out in fire. All of the workers get out before the blaze gets bad. You are told the fire department can't make it to the fire, and the building will burn down.
Do you run into the building to rescue the frozen embryos? Would you answer change if the building burning was an orphanage? (I saw this question first on Eschaton, credit where credit is due.)