Richard Perry/The New York Times  Brooklynâs new face is seen on Flatbush Avenue, with the rising Barclays Center mirrored in the window of Versailles, a year-old party dress store.  The battle over Atlantic Yards has already raged longer than the Civil War, with eight years of protests, petitions and lawsuits seeking to halt a project that promised to reshape the heart of Brooklyn.  Even now, as the oyster-shaped basketball arena that will anchor a 22-acre housing and office complex rises against the low-slung Brooklyn skyline, die-hard opponents are still resisting. Last week they packed a hearing held by two community boards to block the arena from speedily receiving a liquor license.  But almost six months before the Barclays Center opens its doors to the Nets, Brooklyn’s first major professional sports team since the lamented Dodgers, the reality is that the Atlantic Yards project has already done the very thing that critics feared and supporters promoted: transform surrounding neighborhoods prized for their streets of tree-lined brownstones and low-key living.  Shops along the workaday stretch of Flatbush Avenue south of the arena that for generations sold unglamorous products like hardware, paint, plumbing supplies, prescription drugs, even artificial limbs, are seeing new businesses pop up that sell high-heel shoes for $3,500 a pair, revealing party dresses, exotic cheeses and, of course, high-priced martinis. Dozens of restaurants and bars, with beguiling names like Fish and Sip and Va beh’ (Italian slang for “It’s all good!”), have sprouted on major thoroughfares and serene side streets.  “The neighborhood is now becoming an entertainment mecca — anything that’s hip and of the moment,” said Robert Schulman, who fits prosthetic devices for Allied Orthopedics, which has been on Flatbush Avenue for 25 years. “The change was slowly growing, but once the arena came into play, it was exponential. Once a week, a new restaurant or clothing store is opening up.”  The commercial avenues radiating from the arena — through Prospect Heights, Park Slope, Boerum Hill and Fort Greene — had already been undergoing significant changes anyway as a result of the flood of young newcomers to the borough, who have driven up real estate prices and infused the area with an often parodied mix of the trendy and precious.  Along with community gardens and farm-to-table restaurants, visitors will find a purveyor of artisanal mayonnaise, an “eco-friendly bar” made of recycled oak floorboards from an old dairy farm, and, not far from the arena, Bark Hot Dogs, which offers franks topped with “baked heirloom beans.”  But the changes have been visibly accelerated by the construction of the $450 million arena, the flagship of a $4.9 billion housing and office complex to be built over 25 years and known as Atlantic Yards, stoking the fears of longtime residents and even some of the new arrivals that traditions like stoop conversations at dusk and spring bulb-planting parties may be bleeding away.  For Forest City Ratner, the developer of the project, which was strongly backed by many city leaders, the changes are evidence that the arena has already met its goal of transforming a dreary section of Brooklyn — the Long Island Rail Road’s rail yards and surrounding industrial buildings, which the company’s spokesman described as “ a scar that divided the neighborhood.”  “That’s a sign of economic vitality, something that’s good for the borough,” said Joe DePlasco, the Ratner spokesman.  Indeed, some here have watched the construction with excitement, including condo owners who imagine a sharp rise in home values, new shop owners who anticipated the arena in their calculations, and even some longtime merchants looking forward to a surge of foot traffic.  Among these supporters is Moussa Dia, a Senegalese immigrant who owns Versailles, a year-old custom party-dress store that has been featured on MTV, who figured fans heading to Barclays will “notice we’re here.”  “It’s a beautiful piece of art, the arena across the street,” he said. “The face of Flatbush is changing.”  In addition to the many changes that are already visible, opponents are even more concerned about those still to come after the arena opens Sept. 28, with a concert by Jay-Z, the rapper and part owner of the Nets.  They envision their narrow blocks inundated nightly with drunken, celebrating basketball fans — though, to be fair, victories have been few and far between for the long-struggling franchise — and concertgoers still reveling in the music and honking cars stalled in traffic.  The 19,000-seat arena plans 220 events a year. That kind of building should never have been allowed in a residential neighborhood, said Peter Krashes, president of the Dean Street Block Association.
As the opening of the Nets arena nears, glamorous new shops are ascendant on commercial avenues once better known for hardware and paint stores.