According to this article in the UK’s "Telegraph" newspaper, the Vatican (that is, Cardinal Alfonso Lopez Trujillo, head of the Pontifical Council for the Family) said:
Destroying human embryos is equivalent to an abortion… Excommunication will be applied to the women, doctors and researchers who eliminate embryos [and to the] politicians that approve the law.
Please note, though, that the title of the article is "Vatican vows to expel stem cell scientists from Church", but the Vatican is not condemning ALL stem cell research – just that which destroys an embryo. The Vatican has long approved of, supported, and even advocated adult stem cell research. Adult stem cell research (unlike embryonic stem cell research, or ESCR for short) has already had numerous success stories, is morally licit, and the potential seems to continue to expand to the point of almost having the same protential that ESCR promises (but fails to deliver, often with horrifying results).
Unfortunately, this doesn’t seem to make a difference to various large corporations, nor to certain scientists like Elena Cattaneo (a scientist working in the University of Milan) and Prof Cesare Galli, of the Laboratory of Reproductive Technologies in Cremona, who said:
I can bear excommunication. I was raised as a Catholic, I share Catholic values, but I am able to make my own judgment on some issues and I do not need to be told by the Church what to do or to think.
He also "likened the Vatican to the Taliban", according to the article. I suppose it’s only a matter of time before the "Nazi" label is thrown at the Catholic Church (again) for "refusing to help those in need, due to ideology".
Please pray for all scientists, especially those like Prof. Galli who are deluded by their own version of what they think Catholicism is. He claims to share Catholic values. He obviously needs to read "Evangelium Vitae" as a refresher of what the Church teaches about destroying life and why. He also needs to reconsider, if he truly is Catholic, how well he can bear excommunication. His statement is akin to saying, "I can bear not eating. I was raised with food, I share the same tastes as other humans, but I’m able to make my own judgment on the issue of eating and I don’t need to be told to eat by anyone."