20-Year Prospect
As with most jobs, the main difference for housekeepers between now and twenty years from now will probably be technology. Wouldn't you love a laser-zapper to remove mold from tile grout in a flash? We sure would.
Already there are robotic vacuum cleaners that operate on their own. Although, if your family is like most, the small size of the dirt cup in the robot vacuum makes them only semi-useful. Having to empty it frequently doesn't do much for saving your most valuable asset—time.
Nothing, as they say, is forever—except death, taxes, and a bad tattoo. But, for the next twenty years and beyond, we believe housekeeping will be a steady and sturdy career. There's no outsourcing of cleaning a house to an overseas outfit. And, dirt? It only goes away temporarily.
In twenty years, there may even be space colonies on Mars where you could apply your housekeeping skills. Or would that be your space-habitat-keeping skills? Whatever. We have a few years to figure that out.