Before we continue forward, we need to clear up any further misconceptions about the research. We both can certainly agree that embryonic stem cells carry a lot of ethical questions, but let's put that aside for the moment and focus on the science. There are a few things in your latest post that we should address, then we can proceed further.

Quote Originally Posted by phattonez View Post
iPS cells have been used in mice and other organisms, though the transfection method currently used to produce them results in tumor formation
There are a few points within this quote that we should clear up.

1. First, you mention the "transfection method currently used to produce [the stem cell]". It's important to note that there is not one particular transfection method used in this research, but several, and currently there is no smoking gun pointing definitively towards any transfection method being the root cause of tumor formation. In every transplantation, you have a small amount of contamination by non-mature cells, which can lead to tumors. Researchers at Lund University have done studies on how to prevent tumor formation in stem transplants, and published their results this summer in Proceedings of the National Academy of Sciences, should you wish to have a look at the article. There is also a number of theories floating around about other root causes, including a study two years ago which observed a link between cells with highly active mitochondria and tumor formation Mitochondrial Metabolism Modulates Differentiation and Teratoma Formation Capacity in Mouse Embryonic Stem Cells.

2. Tumor formation by stem cells is not limited to somatic, but includes embryonic stem cells as well. Like any other cells, stem cells undergo genetic damage leading to mutations. Because stem cells are so long lived, the potential for accumulation of much smaller damage over a longer period to the genome can act as a seed to tumor formation and cancer growth. Given that embryonic stem cells multiply very rapidly, the potential to form teratomas is high. While this is a drawback to transplantation, consider the possibilities to cancer research, which is what our particular lab is involved in. Over the summer, researchers at UC San Diego working with embryonic stem cells have discovered how to inhibit embryonic cells from forming teratomas, a finding which could presumably lead to new treatments down the road. You can read the article in July's Proceedings of the National Academy of Sciences, or read a summation here: Biology News - UC San Diego Biologists Find Way to Lower Tumor Risk in Stem Cell Therapies

Quote Originally Posted by phattonez View Post
The only disadvantage with iPS cells is...
There are a few advantages to using either somatic stem cells or embryonic stem cells that I posted a few pages back. There are more, but in the interest of not stretching that particular post out, I compacted them to three advantages each.

Quote Originally Posted by phattonez View Post
It doesn't matter if your work was faster because even if you are fully successful with ES cells you cannot avoid the fact that you still possibly face rejection issues. This is not possible with iPS cells.
Believe it or not, I get this quite often. For some reason, people assume that stem cell research is limited to organ transplants and regenerative therapies, when in fact this is just one branch of the research. For instance, our lab is doing research with cancer stem cells. Other labs are doing research with using embryonic stem cells to cure other diseases as well. The research is so exciting because of this. There are numerous scientific articles you can read online or at the library regarding the various avenues this research is travelling, should you wish to read more.

Quote Originally Posted by phattonez View Post
ES cells have not been successful Adult vs. embryonic stem cell success now quoted at 70 to 0 | Geneforum
I couldn't help but notice a glaring omission by Ms. Godfrey when she wrote the following line: "Embryonic stem cells, on the other hand, have yet to prove themselves." While she does go on to acknowledge that the limitations are a factor, nowhere in her blog did I see any mention of the recent advances in embryonic stem cell research, nor of the recent drawbacks to limiting ourselves to induced somatic stem cell research. I wonder what Ms. Godfrey would say about these? Whitehead Institute - Embryonic stem cells reveal oncogene’s secret growth formula ; Epigenetic memory in induced pluripotent stem cell... [Nature. 2010] - PubMed result ; Cell type of origin influences the molecular and f... [Nat Biotechnol. 2010] - PubMed result ; Induced Pluripotent Stem Cells Do Not Fully Replace Embryonic Stem Cells As Disease Models, EU-funded Study Shows

As a general rule, I would avoid blogs as any sort of scientific fact because more often than not, they reflect opinion rather than actual science. While I am sure Ms. Godfrey is amply qualified, my first question to her would be what, if any, research has she done with embryonic stem cells? If none, what - if any - embryonic stem cell research is she familiar with? I don't recall anyone by her name ever calling and talking to me about our research, and I see little on her blog indicating that she has ever delved into anyone else's either. I run into that quite often as well. There are many colleagues of mine who do not work with this particular research, but who have rather strong opinions on the matter. It has nothing to do with their qualifications, and everything to do with their ethical opinion. And that's where the debate lies - not in the science, but the logical inquiry into the morality of it all.