It's inevitable that mortality will be overcome, if not through medical science then through what some call the "singularity", when computer processing power surpasses the abilities of the human brain, in approx 2045. I don't think this would "crack" anything, since such developments will always happen eventually in any sentient race; it's just part of our evolution. There will still be death, through accidents and such, but I think what will become much more prevalent is people choosing to die. Death is only scary because it is unavoidable. Take away the inevitability and the Reaper becomes a friend to those who wish to lay down the burden of life. Those who wish to live will live, those who wish to die will die, and soon I think we will realize that this thing we call "death" doesn't really exist, it's just a changing of form.

CS