George Church is an important figure in the field of genetics, and in recent years has become more vocal in his support for rejuvenation research. He is presently on the advisory board of the SENS Research Foundation, and in this broad article on the near future of medical research you'll find some of his thoughts on aging research:
Aging reversal is a big project both in my lab and in one of our startup companies. This is not about wellness or drugs that affect diseases of aging, which are effects rather than causes; it's trying to get at the causes of aging and reverse them. And there are a fair number of precedents for this in animals, but the idea is to get it transferred to humans.
Reversal of aging: Some examples of this are if you take blood from a young mouse and exchange it with an old mouse. The small molecules, macromolecules, and cells in the blood result in a variety of biomarkers of aging being reversed. You can affect the vasculature, the blood vessels, the nerves, skeletal and cardiac muscles, and there are measures of these that indicate that it's not just prolonging a very aged state or going for longevity; you're actually reversing it.
This is a much better target, in any case, than prolonging longevity because, A, it takes years to decades to even prove that you have extended longevity. Also, if you've done it on somebody that's quite old, the economic consequences are dire; that's the part of your life where you spend huge amounts on medicine and don't improve the quality of life tremendously. If you can reverse it to an age where you essentially don't use any medicine, this will be much more cost effective.