"We're working on assembling retailers that are upscale and appropriate for the idea we have of the expansion, to ensure its success," Watson said. She did not disclose which retailers the mall is courting, nor when construction on the expansion will begin.

Regardless of the market — urban or suburban, wealthy or working class — all of the announced developments intend to implement at least some of the outdoorsy, "pedestrian-friendly" milieu exemplified by The Gateway. Which, incidently, is also in the midst of its own multiphase expansion.

The timing of the Utah projects and the broader industry's shift toward mixed-use lifestyle developments aren't coincidences, according to Jim Wood, director of the Bureau of Economic and Business Research at the University of Utah.

"A lot of it has to do with the fact that retailers see opportunities and then try to jockey for position. But it's all driven by rooftops: by population growth," Wood said. "We're a high-growth area, in which incomes and wages did pretty well in 2005. And if you look at where these projects are, they're in areas where you have tremendous residential and population booms."

More generally, lifestyle centers work because "the shopping patterns and consumer habits of the typical shopper have changed," said Jake Boyer, president of The Boyer Co., developer and owner of much of The Gateway.

"People don't just want to go and have a bland shopping experience by going to a single-purpose shopping center," Boyer said. "They want a more global experience, which entails a combination of shopping, eating and entertainment. The ICSC has proven that with these lifestyle centers, people spend more time hanging out, which typically translates to more dollars spent."

Wood and Kavanagh said the timing of these projects also reflects a cycle of sorts, a circle of mall life.

Most of the nation's enclosed malls were built around the same time — the 1970s and 1980s — when many of them were "the only game in town." But over time, Kavanagh said, communities grew, attracting more retail. Life sped up, and people began to look for a more consolidated experience — one place where they could find food, stuff, entertainment and ambience.

Add to that the advent of online shopping, and competition for consumers' dollars has rarely been more heated. Retailers and developers need every edge they can get, he said.

"To find consumers, they need to renovate, expand and even change their configuration," Kavanagh said.

He said the lifestyle center movement reflects, at least in part, the changing face of the industry itself: the changing needs of retailers like Borders and Barnes & Noble, which have expanded their offerings to include cafes, electronic entertainment and other merchandise; and mergers among department store chains, creating fewer players and an increasing chance for market redundancy.