The more I think about it, the more I think only two options remain to make middle-class money or better.

1- take the King’s Shilling, as Rob says, and work in the old culture - receive few, but sizable, amounts from a stash controlled by few people, through a good connection with one of these people. High-end consulting is technically part of #1: even if you're not directly on the customer's boat, you depend on its engine to move your own boat.

2- exploit innovative technology to operate an enterprise that scales up to deliver value to large numbers of low-paying customers, and thus receive a large number of small amounts through a large number of relationships with customers.

In both cases you can expect to face competition. #1 is mostly social/political; #2 is mostly technological/creative.

In the long term, I think #1 is like staying on a chunk of ice floating in warm water. There is less and less room as the old culture melts down, and people will inevitably get shoved out as budgets shrink.

#2 is an open field. It's the Wild West, where the rules are not very clear and the territory itself appears to be limited only by our imagination. The name of the game is to find a way to make it work in the ecosystem you're living in.

There is volatility and uncertainty in both markets. Assured comfort is out for the foreseeable future.

I find that knowing how to get the same quality of life out of less money is indeed a form of personal wealth - you could say that it improves personal productivity on the spending side.

I recently learned about a physicist who retired at 33, after saving 3/4 of his salary for 5 years. His secret? He simply figured out how to live on much less money, thereby turning his modest savings into a retirement-worthy pile of money. (Not having kids surely helped, too :) If you're curious, his site is here: http://earlyretirementextreme.com/