While its easy to lose perspective amidst the daily grind, we do in fact already live in a science-fiction future, in which researchers are earnestly engaged in engineering the human body and its component parts. For example:
In one study, out of Germany, 35 patients who received bone-marrow stem cell transplantation during coronary artery bypass surgery achieved "excellent long-term safety and survival." Ten patients who received similar transplantations after repair of mitral valves also fared well, with improvements in the heart's pumping capacity. Slovenian investigators had similar success, with improvements seen in patients with advanced heart failure who received bone-marrow derived stem cells. There were also advances in gene therapy reported, with Singaporean researchers using nanotechnology to deliver genetically modified cells to help heal heart attack damage in rabbits.
Transplanting fetal neurons into the brains of young mice opens a new window on neural plasticity, or flexibility in the brain's neural circuits. The research [suggests] that the brain's ability to radically adapt to new situations might not be permanently lost in youth, and helps to pinpoint the factors needed to reintroduce this plasticity. ... If scientists can find a controlled way to trigger plasticity in specific parts of the brain, it would open new avenues for treatment of a variety of ailments. Adults who suffer brain damage from stroke or head trauma have some level of reorganization in the brain - enhancing that plasticity might improve recovery.
That second article goes hand in hand with recent research in mice in which transplant of fetal stem cells extended median life span. There are clearly interesting processes associated with fetal cells. Given the advances in engineering induced pluripotency in recent years, it is not unreasonable to expect that, should studies continue to point towards positive results from fetal stem cell transplants, researchers will find ways to reprogram normal cells into a fetal-cell-like state.