That is a solution we will have to use to some extent. "Work 'til you drop" is a realistic answer to what's wrong. The whole notion of "retirement" is actually a rather new idea among human beings. So long as people are producing at least as much as they consume, they are not a drag. At least, not on the economy. I'm not sure what the social effects are of having a generation that does not "get out of the way." We've never had that issue before. In George Washington's day, the average life expectancy was 45. Imagine if Corporate America was run by guys like Strom Thurmond and Robert Byrd. I don't think it would be good.
The real drag is going to be medical costs. Fixing bad hearts, joints, and etc isn't cheap.