I bet there are alot of empty PC chairs right now. In fact, is that the shuffling of old feet and the squeak of wheel chairs I hear?
Living for 150 years would be murder on the Social security system, and just about any other underfunded saving plan.
Eventually, if human lifespan does increase greatly, two things will happen. First, retirement age will no longer be a set number. If you aren't facing the prospect of losing your ability to be productive, you don't have to worry so much about planning around it. If people start regularly living to be 150 and increase their productive years as well, it will all work out. Retirement age could then be 120.
The problem will be if people age just as much, but don't get sick and die until later. That would be a disaster, and it doesn't seem possible.
Second, retirement will be tied to your economic condition more than anything else. You will be able to retire when you have a sustainable investment income. Retiring at sixty will seem like retiring at thirty does now.
As long as death is in the picture, you can still amortize that retirement income, but if humans ever do become effectively immortal it will be necessary to sustain that investment indefinitely.
Save Soc. Sec NOW! Light up!/sarcasm off