In the longer run, the asteroids are where it's at. Raw materials, solar power up the wazoo, and no gravity well when you want to fling ingots of platinum and chromium back to the Earth-Moon system.

With enough infrastructure, lunar mining becomes feasible, but you really need catapults. Good news: refined materials don't care what you accelerate them at, so short catapults work.

In the shorter run, it's probably tourism. Although Earth-orbit facilities will start out making more money than lunar ones. Better scenery, less transportation.

Or maybe they'll just keep a lunar science base going. I notice that they've had big science stations at the South Pole for decades, constantly manned, and so far I don't think they've made a nickel at it.

We may be too pessimistic. Two hundred years ago, if I had told someone I could leave San Francisco and be in England in half a day, he would have thought I was nuts. Look at modern Honolulu sometime. Every bit of that had to be brought over on boats.

If someone figures out how to make a lot of money in space doing something you can't do anywhere else, people will go there.