There are currently two schools of thought in the transhumanist community:
One, which you’ve mentioned, revolves around the idea of overcoming the limits of DNA. Research into various creatures, including (but not limited to) the jellyfish fall into this camp.
Their general goal seems to be that we should work to reverse our aging process, then create a mechanism by which cells are constantly repaired perfectly, and the used garbage cells are flushed out…preferably without causing cancer when they do.
The second school of thought, the one which I belong to, takes a different approach. Our idea is that life extension could be achieved through technological innovation revolving around shedding the body entirely.
Instead of concerning ourselves with keeping the entire body alive, we should focus on the development of nanotechnology for the purpose of keeping the brain alive indefinitely.
With the ability to build new, custom bodies that we merely move the immortal brains into, any catastrophic accident would become more of a nuisance than anything else.
Additionally, being able to build custom bodies resolves numerous issues with old bodies that a simple age reversal would not address:
What if we wanted to be taller, shorter, a different color, race, face, or gender? Suppose we want to alter our eye color? These last two can be done with present technology, but a male to female operation does not provide the ability to become pregnant, and altering a persons eye color comes with the serious danger of the permanent loss of sight.
Certainly, a face can be altered through plastic surgery, but that wouldn’t improve your singing voice, nor would it increase your tolerance to pain.
The custom body solution is one which resolves all these issues, while also providing opportunities for augmented physical performance like speed and strength.
To get from here to there, however, isn’t a straight line. Long before we learn to build a custom body which can serve as a life support system for the brain, we will need to first learn to build a life support system for the brain.
Such a life support system will require certain additions to the brain. Probably the most obvious of which would include a working interface for an autonomous machine capable of providing the necessary feedback to the brain to make it believe that it had a body and was in an actual space. True, both the body and space would be virtual, which means that all apparent items, lighting, weather etc. would be nothing more than pixels easily manipulated by the computer.
One theory about the brain is that it is a functional organic device capable of accessing intrinsic information in quantum space and time. Enhancing such a device via what would amount to external memory backup (required for the disembodied state) could provide a far better lifestyle than anything available to most people on earth. After all, when a house, car, or other toys amount to nothing more than pixels, there really is no reason not to provide the very best.
In such a state, we would of course be free from the tyranny of the external devices required for transportation ( Spacecraft, automobile, aircraft, etc. ) With no expenses to speak of and the ability to master any subject at will, the only remaining requirement for life extension would be nanoscale technology capable of repairing and replacing damaged or decayed cells using materials of a more stable substrate than meat.
With little more than time on our hands and autonomous machines to keep us alive forever, there is no reason that humanity might not focus on the next step in the process: designing new, artificial, full body prosthetics to house our brains.
Naturally, any catastrophic injury would become, at best, a nuisance. New prosthetics for the brain could easily be brought in to replace the old full body prosthetic at will. Not all would choose the dangerous of the organic world, of course. Some would remain in a virtual environment by choice or for purposes of convenience. For example, an extended journey to another world would require the use of limited space for full bodies, meaning that life in virtual space would greatly relieve the need to carry endless amounts of food to support bodies which, frankly, would just be a pain to try to maintain.