For those who've been following the race for the tallest building over the past few years, you're probably familiar with the Al Burj (a.k.a. "The Pinnacle" and "The Tower"), proposed back in 2003. At first, I thought this "Nakheel Tower" was not a new project, but simply the latest incarnation of the Al Burj. It's difficult to tell whether Nakheel has scrapped that project for a completely new one, because the specs and proposed locations have changed a few times. The design shown in the article does look significantly different from the (original designs), though, and it appears that Nakheel is still determined to surpass the Burj Dubai's (developed by Emaar) height, if at all possible. In September, the Burj Dubai became the tallest man-made structure ever built, and it should be completed sometime next year.
Meanwhile, Nashville's Signature Tower is still on hold.
EDIT: I found this news item about the Nakheel Tower on Nakheel's website, but I don't see anything about the Al Burj or whether this is the same project.