The cells were not taken after the baby was born, they were taken during pregnancy. The risk to the mother and child in extracting small amounts of amniotic fluid are small but real -- my guess is this was done using fluid extracted to test for fetal anomalies.
And the cells are not embryonic, embryonic refers to cells in their earliest stages, when the embryo is in the 1-10ish cell range, before there is any differentiation.
The undifferentiated cells "seem" to have promise because they can be "anything", but so far it turns out being able to be "anything" has meant that they can't really be "anything useful" -- like there is too much possible variation to make actual use of the cells.
Even if this new source of stem cells doesn't provide stem cells that are useful, who cares? It's not the performing of research that leads to dead ends that is the problem with embryonic stem cell research, it's that for many people that research is KILLING BABIES, terminating human life.
The argument that embryonic cells are useless may be truthful, but it is a dangerous one -- it argues that if embryonic stemm cells actually WERE useful, then it would be OK to kill babies. However, we were losing the argument, and some people who WOULD be willing to kill babies to save themselves would join our side if they thought the killing was for no purpose at all.
With new ways of getting these stem cells, we can stop arguing about whether research will lead to cures, and simply argue on the merits that you shouldn't kill humans to try to save other humans.
You misunderstand where these stem cells are coming from. They are not samples of fluid taken during pregnancy but instead are captured after live birth in the amniotic fluid resulting from birth. This represents a breakthrough. Read this article for a better understanding. The researchers say that the cells captured AFTER birth can be used not only for the child in later years but for 99% of the population.
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/01/08/STEMCELLS.TMP
As you know, that hasn't been the underlying reason for the abortions, they were done for the abortion sake alone. The stem cells were the straw man.