The projects presented at Cityscape Global 2012, the real estate trade fair taking place at the Dubai International Convention and Exhibition Centre, are giving off an aura of optimism in the wake of a slow recovery after the global 2008 bust. The market has trended upward for three quarters in a row for the first time since 2008, while Dubai residential constructions rose 23% in the past year, according to the last quarterly report by analysts at Jones Lang LaSalle. Apartments at a project called The Address The Blvd, a 62-floor, 340-meter skyscraper with 200 hotel rooms and 542 serviced residences, sold out last week faster than tickets for a Justin Bieber concert - in under 24 hours. Three days ago, people lined up around the block to get their hands on one of the 360 villas at Jumeirah Park, a new 3.5-square-kilometer development, to the tune of one million euros each. Among the projects presented at Cityscape was the Meydan Tower, to be built in the heart of Dubai, on Sheikh Zayed Road. It will integrate vertically all the residential, commercial, sports and entertainment elements of a horizontal neighborhood. Also at Cityscape on Thursday, Link Global Group President Arun Mehra, announced a project called Taj Arabia, a marble copy of the Taj Mahal but four times bigger, to be built in Dubai within the next two years to the tune of $1 billion. It will have a 300-room hotel and 200 luxury apartments, and will be aimed at couples wanting to get married in romantic, deluxe surroundings But some analysts have warned against excessive optimism. The fact that people are spending big money on real estate again \'\'is worrisome,\'\' because it could open up a Pandora\'s box of speculative transactions just like in the pre-2008 crisis boom, said Matthew Green, head of research at CB Richard Ellis real estate consultants.