More attention is going towards the relationship between degenerative aging and mitochondrial dysfunction - given that this is one of the seven pillars of Aubrey de Grey's SENS, I think that this is a good thing. From the Life Extension Foundation News, a brief note on recent research: "Cumulative [mitochondrial DNA (mtDNA)] damage occurs in aging animals, and mtDNA mutations are reported to accelerate aging in mice. We determined whether aging results in increased DNA oxidative damage and reduced mtDNA abundance and mitochondrial function in skeletal muscle of human subjects ... These results demonstrate that age-related muscle mitochondrial dysfunction is related to reduced mtDNA and muscle functional changes that are common in the elderly."
Link: http://www.lef.org/news/LefDailyNews.htm?NewsID=2315&Section=AGING