The building is complete and the height has been revealed. The tallest man made structure that has ever been built is 828 m (2,717 ft) tall and is now called the Burj Khalifa. The height of the tower, which was one of the most closely guarded secrets during construction, was flashed onto a giant screen during the inauguration before a 400,000 strong crowd. Estimated to cost around Rs.6900 crores (US $1.5 Billion) the building was officially inaugurated on January 4th amidst flashy fireworks and much fanfare. Wikipedia lists these as the records currently being held by Burj Khalifa:

Tallest skyscraper to top of spire: 828 m (2,717 ft) (previously Taipei 101 - 509.2 m (1,671 ft)) Tallest structure ever built: 828 m (2,717 ft) (previously Warsaw radio mast - 646.38 m (2,121 ft)) Tallest extant structure: 828 m (2,717 ft) (previously KVLY-TV mast - 628.8 m (2,063 ft)) Tallest freestanding structure: 828 m (2,717 ft) (previously CN Tower - 553.3 m (1,815 ft)) Building with most floors: 160 (previously Willis Tower - 108) World's highest elevator installation World's fastest elevators at speed of 64 km/h (40 mph) or 18 m/s (59 ft/s) (previously Taipei 101 - 16.83 m/s) Highest vertical concrete pumping (for a building): 606 m (1,988 ft) (previously Taipei 101 - 449.2 m (1,474 ft)) Highest vertical concrete pumping (for any construction): 606 m (1,988 ft) (previously Riva del Garda Hydroelectric Power Plant - 532 m (1,745 ft) ) The first world's tallest structure in history to include residential space Highest outdoor observation deck in the world World's highest mosque (located on the 158th floor) World's highest installation of an aluminium and glass façade, at a height of 512 m (1,680 ft) World's highest swimming pool (76th floor)

Architect for this engineering marvel was Skidmore, Owings and Merrill, Via and Via.