Andrew Sullivan is a dubious source of information.
The scientists who made this discovery have already stated that Bush’s restrictions on funding set back this area of science by years and that the discovery doesn’t obviate the need for embryonic cells.
In all honesty the debate is ridiculous. Every day thousands of embryos are spontaneously aborted. Pregnancy is a risky event and loads of things can cause it to end early. Genetics, stress, illness, diet, etc, etc. We as a society let millions of born humans starve to death and allow/cause millions more to die in war.
Even without that context I find nothing morally troubling with abortion, but within that context I find overblown concern about abortion morally troubling.