The building is called the pinnacle and consists of 3 separate towers joined at various levels with huge atriums between in its hollow middle. It has two huge spires and is on display at the Nakheels office
Could be worlds tallest tower at 750 beating the released height of the Burj Dubai Tower. Currently under consideration due to impact on the Palm. Another Location may be found it this does not go through

Please do not forget: this is just proposed, not approved. but if I remember well I think I’ve heard that Dubai wants to build it. if it's impossible on palm jumeirah (such a building is really heavy and may push down that part of the island where it will be situated). so if it's not possible on palm j they intend to build it on the continent!