But you probably don't have any idea why. Here's one possibility - telomeres .
The thing that's overlooked in that quote is that telomeres probably aren't the primary cause of aging. In fact no one really understands what is. However once a telomere shortens to a certain length, the cell becomes senescent. It's call the Hayflick limit

The institute that cloned Dolly however claims that shorter telomeres weren't the cause but even they admit that her's were shorter than would be expected for an animal her age. Their argument is that telomere length is restored by the cloning process but I suspect there is some doubt about that given that you're starting with a somatic (body) cell.

edit: The bottom line is that cloning is a very different process than starting with a normal embryo. I only made the association to show you that this technique of transplanting the nucleus from one cell to another is very old news. I wasn't trying to argue it wouldn't have any repercussions. Maybe you were trying to change the subject though?

And my point was that this isn't anything new from a technical perspective. Nuclear transfer is a technique that's been around for decades. Maybe I should have been clearer that I was talking about the technique but I certainly never argued that the procedure was safe for use on embryos.

I think what has people upset about this is the fact that it's so much like cloning, which is also old news. So this debate has been going on for decades. It's just that now they want to apply nuclear transfer to humans. In fact my guess as to why they've only done partial transfers of mitochondria in the past was due at least in part to a desire to avoid this debate as well as the uncertainties seen with cloned animals.

For example in doing a little research since my last post I found that in some cases you actually get telomeres that are longer than you would normally find in certain species of animals . That's a pretty interesting page if anyone is interested in the possible side effects of cloning.

I'm not sure what you mean, but it looks like the issue is the hands of the FDA now. My guess is that they'll veto it but for desperate couples, I'm sure the procedure will still be performed someplace else in the world. You can't stop technology, even when pursuing it may not be the wisest choice.