The difficulty with all these doom-and-gloom scenarios is that don't take into account the fact that intelligent men and women adjust to changing conditions. Healthy 70-year-olds who want to start new careers other than the ones they've been stuck with for a "lifetime" will have the time to do so. That isn't a bad thing. And those careers will not be in competition with the young pups in most cases. It was fun, but I don't want to be a stud in a Turkish harem anymore - let the young folks do that now.
Anyway, I have a backup plan. We increase the retirement age to 64 on my 65th birthday, to 74 on my 75th, raise taxes to support the whole thing, and the X'ers WILL BE MY SLAVES FOREVER!!! MOOOHAHAHAHAHAHAHA!!!
Sorry.