Some of the country's biggest and most successful investment firms have amassed an estimated $7 to $8 billion to buy thousands of foreclosed single-family homes. They plan to fix them up and rent them.

Yes, they know that about one-third of the 40 million households that rent live in single-family units, but the investors don't intend to become landlords. No, they're speculators and believe that in the next few years the value of these bargain-priced foreclosed units will soar as the housing industry recovers. They're hoping for 200 to 300 percent returns on their money.

In the meantime, most of the players in the housing industry proper still seem semi-paralyzed and prepared to sit tight until...well, who knows when. Wonder who's making the better bet?