They said it nearly 40,000 rooms when the city had 90,000 rooms, Now the number is nearing 135,000 rooms.

Hotel room growth of this measure is unprecedented; no other city has seen such constant and sustained hotel development over so many years. Now it looks like Las Vegas will continue to expand as long as there is capacity at the airports and on the roads. The development of Las Vegas is of course due to a perfect storm of crossroads as the desire for gambling, high quality meeting space and great cuisine combined with cheaper travel and the desire for the typical American consumer to have a safe place to play free from socio-societal judgments.

But forget psychology, this next era of Las Vegas is as big as the last boom that saw the rise of Bellagio, Venetian and Mandalay Bay, amongst others. Now a recent flurry of announcements is set to transform the city by 2011. On tap are a series of massive new projects that will blow the mind.

Opening in December is Palazzo, a sister resort to the Venetian. It’ll have more than 3,000 rooms, a high end shopping plaza featuring a Barney’s New York and more than 100,000 square feet of gaming space. Wynn Las Vegas is also getting a new sister hotel, Encore, set to open in November 2009 at a cost of $2.1 billion. Meanwhile site work has started on the $4.4 billion Echelon Place, a 5,300-room resort featuring the 3,300-room Echelon Resort hotel and three other hotels set to open in 2010. That project is being run by Bob Bougner, who was responsible for building the market shifting Borgata in Atlantic City.

Also on tap is colossal MGM City Center in Las Vegas, which at more than $7 billion is the most expensive project of its type undertaken. It’s rapidly rising on The Strip and when it opens in 2009 will feature a glass-clad 60-story, 4,000-room hotel/casino and three 400-room non-gaming boutique hotels.

Next door to CityCenter and also under construction is The Cosmopolitan, which seeks to grab design savvy guests with a mix of boutique distinction, urban design and technological advancement. The Cosmopolitan will feature 2,998 condo-hotel and hotel rooms set inside two 600-foot-tall towers. The towers are perched atop a four-level, 100-foot-tall lower podium. The sleek, iconic architecture provides direct accessibility to all full-service amenities, including more than 150,000 square feet of integrated ballroom, business, convention & meeting/conference space, a 40,000 square-foot spa, salon & fitness center and an 80,000 square-foot casino incorporating the most advanced gaming technology.

Also coming is a $5 billion multi-use development project from El Ad, which owns the Plaza in New York. There will a Plaza hotel here as part of the 3,500 rooms, private residences and retail space.

Coming next year is the Trump International Hotel and Tower, which at $600 million is the year’s big project.

And BearSterns indicates the city can handle it. In a just released report, the company states, “The Las Vegas Strip is a unique market in that new capacity (as measured by room supply) typically stimulates room demand, visitation volume, and increased spending levels. In fact, in each year that supply grew by more than 8%, room demand grew on average by 10.4%. While much of the demand side of the equation depends on the state of the U.S. economy, we think history suggests that new Las Vegas development will spur increased visitation volumes as it has in past years,” the report said.

With news like that you can expect the Las Vegas mega resort to continue for decades to come.