"This is definitely a national issue," Gaston says.

Retail numbers seem to hold that up. The national vacancy rate for neighborhood and community shopping centers rose to 7.7 percent in April—the highest amount of unleased space since 1996, according to Reis, a real estate research firm.

At the same time, rents fell in 31 of the 76 markets the group monitors, according to Reis' chief economist, Sam Chandon. He adds that rental income is likely to drop even further this year as new retail space that was started during the boom becomes available, glutting the market.

"Consumers are under pressure, and there's more job losses to come, which will significantly crimp retail activity," Chandon says. "And there's nothing like job losses to put the fear into people and make then start saving."

Large national retailers are bracing for lower sales by closing stores. Ann Taylor, Talbots, and Macy's are among those planning to shutter locations recently. Macy's, the venerable New York-based department store, pulled up recently from the Valley View Center in Dallas—and said it would close eight other stores this year.

"When an anchor like [Macy's] closes, it affects the ability to lease any space," says Chandon. "Shopping malls depend on anchors to draw in other tenants."

Creditors haven't missed these signs either. Many developers have suddenly had banks demand more equity before agreeing to loans, or have seen loan agreements come back with lending rates so high that they're not willing to sign.

"This started to hit about August 2007," says Scott Lynn, a Dallas-based principal for Metropolitan Capital Advisors, which secures financing for real estate developers. "We have definitely noticed a slowdown in financing from the Wall Street conduits and securitizing lenders. It's been a very significant pull back."

Even small neighborhood strip malls are not immune from the economic slowdown, though their focus on supermarkets and other stores that sell staples used to make them resistant to downturns. Cash-strapped customers are passing them by for big-box retailers.

"Consumers are much more value conscious—even for groceries," Chandon says. "So these stores and neighborhood malls are not completely immune this time around."

Yet not everyone is reading these signs as time to close up shop. For existing mall owners, rents will eventually rise as less retail space gets built, says Robert McMillan, an equity analyst with Standard and Poor's.

"If you curtail supply," he says, "rental rate growth will gradually increase for existing players in the market."

That's little comfort for developers. With the economy in a funk and consumers just spending less, developers say they're not expecting the high life again for quite a while.

"This is not a cycle I've seen before," says Gaston. "We just got out of the biggest boom in development in years. So even when we do come back, I don't expect it's going to be at levels we've previously seen."