Right or wrong, not whether it works, is the issue
Hwang noted that with cloned stem cells we would be "treating our bodies with our own perfectly matched cells,"
Well, no not really. Technically, we would be treating our bodies with our own twin's cells. That may seem nuanced, but the difference is vast. It is the difference between using my body and using another's body that was destroyed in the process.
However, considering his results so far, Hwang may actually succeed in using human embryonic stem cells as a treatment. "I promise that our medical researchers are working non-stop," concluded Hwang.
So saying there has not been a single trial of an embryonic stem cell therapy may be a lot like saying in 1902 that "heavier than air flight is impossible." It's true until it's not.
I don't think our main line of reasoning is that it WON'T work, but rather that it is an immoral choice. Whether is works or not is secondary. First we have to decide is it "right" or not.
But, in the mean time while we debate the ethical ramifications of ripping apart human embryos for "therapies", why don't we focus our limited resources on adult stem cells; cells that are already curing 65 different diseases and showing more promise every day.