This June, at the Documenta 12 art fair in the picturesque hill town of Kassel, Germany, the gallery-going set might notice an unusually homogeneous group mingling among them: 1,001 Chinese people all dressed alike. But the fair hasn’t mandated a uniform; the mysterious visitors will be part of a living, breathing, schmoozing installation by the artist Ai Weiwei.

Ai is one of several Chinese contemporary artists exhibiting at the influential fair, including painters whose works have been flying off the auction block for well into the six figures. Ai, who will be trying to sell a few sculptures in the show, says his human canvas is a commentary on the Chinese art rush.

China’s artists “concentrate on how much money they’ve made, but there’s no imagination,” says the 50-year-old Ai, whose $4 million project will be funded in part by his Swiss dealer, Urs Meile, and three private Swiss foundations. “It’s just China’s hype.”

Now, a year after China’s hype caused prices for contemporary Chinese works to explode at the major international art sales, this spring’s auction season is likely to be an important indicator of the market—and whether, as some say, it’s a bubble about to burst. Collectors will be paying especially close attention to a series of May auctions: Phillips de Pury’s contemporary sale in New York and Christie’s events in both Hong Kong and New York, where Yue Minjun’s Picnic (1995) and Zhang Xiaogang’s The Sisters (1996) carry estimates of $500,000 to $700,000.

One view is that the genres of art that have seen the most spectacular price run-ups—Political Pop, which uses colorful, iconic imagery, and Cynical Realism, a style that focuses on psychological portraits of contemporary China—are the most overvalued. These cartoonish, often sarcastic works have been top sellers because they have an obviously Chinese look but are also accessible to Western buyers. “Collectors new to the market who aren’t sophisticated are going for familiar names and want a recognizable Chinese icon,” says Chin-Chin Yap, a contemporary-art specialist at Phillips de Pury. “Soon there will be a shake-up.”

One prominent collector, Giulia “Kika” Borghese, unloaded 41 Chinese contemporary pieces—raking in $4.7 million, well over the high estimate—at Phillips de Pury in February, according to people familiar with the sale. Todd Levin, curator of hedge fund manager Adam Sender’s collection of more than 700 works, calls Chinese contemporary art “a consumer category, not a collector category.” And George Lindemann Jr., a major collector in Miami Beach, has sat out the trend. “It went up in value so fast, I probably missed it,” he says.

Some specialists say that Chinese contemporary art that doesn’t look so, well, Chinese may have more staying power. This category comprises a huge variety of photographers, painters, and sculptors, whose work echoes everything from Old Masters to Lucian Freud. Agnes Gund, president emerita of the Museum of Modern Art, bought pieces by a handful of these artists last year, including two of Cai Guo-Qiang’s well-known gunpowder works.

While auctions and collectors are good short-term market indicators, it’s museums that determine who will be important in the long run—and they’re just now starting to devote major resources to Chinese contemporary art. The Guggenheim recently added a full-time curator and is planning a show for early next year. The Tate has started acquiring works. And the Centre Pompidou plans on opening a branch in Shanghai by 2010. But for now, says Melissa Chiu, director of the Asia Society Museum in New York, “the ball is in the court of the private collectors.” One of the most influential of those collectors, Charles Saatchi, snapped up a $1.45 million painting by Cynical Realist Zhang Xiaogang last fall. A spokeswoman for the Saatchi Gallery says her boss is still buying—and isn’t selling.

As for Ai, his art may ride out any bubble, because he’s best known for his architecture—he’s a co-designer of the bird’s-nest-shaped stadium for the Beijing Olympic Games—and large-scale conceptual projects like his Documenta stunt. Say what you will about his work, it certainly doesn’t fall into the Pop Art category. (His most recent solo American show, at the Robert Miller Gallery in New York, featured $12,000 snapshots of himself giving the finger to various world monuments, including the White House and Berlin’s Reichstag.)

Ai is convinced the market is inflated but declines to predict the future: “It’s like you see a play and you try to follow the feelings to follow the story—but you never know how it will end.”