Dubai is getting the world's tallest building with the Nakheel Tower. The Nakheel tower will have a height of over 1km (~0.62miles) and mark the center of Nakheel Harbour & Tower.
The Nakheel Harbor & Tower development will have the world's only inner city harbor and sprawl across an area of more than 270 hectares and become home to more than 55,000 people, a workplace for 45,000 more and attract millions of visitors each year.

"There is nothing like it in Dubai", His Excellency Sultan Ahmed bin Sulayem said at the launch. "Nakheel Harbor & Tower is located in the heart of 'new Dubai', where we have focused on creating a true community, a location for living, working, relaxing and entertaining, for art and culture. All of this is concentrated in one area."

The Nakheel Tower is supposed to be finished in 10 years. Until then Dubai already has the tallest building with the Burj Dubai which reached 707m in September. It is still under construction.
More details on the Nakheel site.