It is plausible that mechanisms of unlimited tissue regeneration will be learned from lesser species and then ported to humans: "Urodele amphibians such as the axolotl are the champions of tissue regeneration amongst vertebrates. These animals have mastered the ability to repair and replace most of their tissues following damage or amputation even well into adulthood. In fact it seems that the ability of these organisms to regenerate perfectly is not affected by their age. In addition to being able to regenerate, these animals display a remarkable resistance to cancer. They therefore represent a unique model organism to study regeneration and cancer resistance in vertebrates. The need for this research is even more pressing at the dawn of the 21st century as we are faced with an ever aging world population which has to deal with an increase in organ failure and cancer incidence. ... studying tissue regeneration in salamanders could yield significant knowledge to help regenerative medicine achieve the desired goal of allowing humans to repair and regenerate some of their own tissues as they age."

Link: http://www.ncbi.nlm.nih.gov/pubmed/18814845