NotaSocalist, you may be able to prove it (or disprove it) for yourself. Look up published data from trustworthy sources on the height and number of floors of the Sears Tower, the Taipei 101, the WTC, and so on. This will give you a general idea of the ratio of floors to height of the tallest skyscrapers. Then, relying on whatever photos you feel you can best trust, count the number of floors visible in the Burj Dubai. Apply your ratio and you will have Burj's approximate height.

The thing to understand about Dubai-- those guys will do a thing just because it is an unusual idea, not because it is a good idea. They never think about whether something is a good idea. They build thngs like indoor ski slopes because they can, not because any serious ski enthusiast would go to Dubai for the skiiing. Let them enjoy their money-- with their sort of mindset, they won't have it for long.